- write whole SEG-Y file or part of it to disk in SEG-Y (IBM-32/IEEE) or CWP/SU format with ability to select data on base of trace index or trace header value or trace header expression and given time interval; reversal trace order is also supported. Processing parameters can be applied to recorded data (filter, AGC etc).

- export trace(s) sample and header values to text file

- import trace headers values from text file

- trace shift according with “Delay Recording Time” trace header value

- selection of traces to be displayed by trace index or header value and by expression

- trace headers change by means expressions

- open and fix files containing wrong data in binary header (Recovery Mode)

- single trace header item editing

- disc directory browsing

Modification History

SeiSee Version	Description
1.0	The program name has been changed so as too many programs have same name Improved user interface, new graphic display module
1.1.b2	Very big files support
1.4b	Weighting factor support
2.0.b0	Command line startup mode with SEG-Y name as the first parameter; File Reopen menu added; Custom trace header item descriptions Automatic PC byte order detection (Big/Little Endian ) Scrolling seismic image by left mouse button
2.1	Trace data samples browsing (text table) added
2.2	Trace increment option added to Selection dialog
2.3	New options: Trace selection by expressions and trace headers modifying.
2.4	IEEE Float4,8, IBM Float*4 formats support in trace header
2.5	Open and fix files containing wrong data in binary header (Recovery Mode) Saving file with reversal trace order
2.6	Display trace header as integer values array dump for nonstandard data analysis
2.7	Search trace by header item value. Single trace header item editing
2.8	Record SEG-Y file with processing applied Separate gain control for wiggle and color mode
2.8	Trace selection by header value expression during saving SEG-Y file
2.10	Save trace samples to text file
2.11	Trace header values import from text file
2.12	Disc directory browsing
2.13	Нeader panel (Info) separated from seismic tab
2.14	Reading of CWP/SU files
2.15	Saving to CWP/SU files

Starting the program

Double click program icon by mouse:

Main window will be shown

Use button to toggle controls panel visibility, and for directory browser.

Command line startup mode is also supported. Use first parameter to specify a SEG-Y file name

Using the program

Open SEG-Y (CWP/SU) file

Select menu “File” ® “Open ”, or press button: .

Standard “Open” dialog appears. Use it for to select file that you want to browse

Select menu “File” ® “Reopen” to open one of previously opened files.

Open Directory Browser panel

Select “File” ® “Open Directory” menu. Standard “Open” dialog appears.

Use it for directory selection, then select any file in it and press “Open” button.

The Browser panel will be shown:

(Only valid SEG-Y and CWP/SU files will be listed)

To display SEG-Y file just select it in the list by mouse.

The panel buttons:

- Return to the previous directory

- Refresh directory list

- Open directory selection dialog

Open file in Recovery mode

If file has wrong values in “Sample Interval”, “Number samples per data trace for reel” или “Data Sample Code” items of the binary header, the program opens file in Recovery Mode. Only text and binary header will be read. It is necessary to fix the values and reopen the file again.

Selection of traces to be displayed

To change the parameters choose “File” ® “Trace Selection” menu, or press button.

Trace selection by trace number or header item value

Choose “By Number” tab, then fill in selection parameters form and press “Select” button, after this the program will start trace selection. When it is done, press “OK” button to display selected data or “Cancel button” to discard the selection.

Trace selection by expression

Select “By Expression” tab, then enter expression text, and press “Select” button, after this the program will start trace selection. Expression syntax is described in the “Expressions” appendix. When it is done, press “OK” button to display selected data or “Cancel button” to discard the selection.

Saving data to SEG-Y or CWP/SU file

To save file select “File” ® “Save As ” menu item or press button.

It is possible to save all trace or part of them. Fill selection parameters in the dialog. Selection parameters are the same as described in “Selection of traces to be displayed” chapter.

Check “Reversal order” checkbox to save traces in reversal order. Check “Apply Processing” to save data with processing applied.

Then press “Save” button. When standard “File Save” dialog appears, use it to specify output file. “Close” button discards dialog.

Then press “Save” button. When standard “File Save” dialog appears, use it to specify type and name of output file. “Close” button discards dialog.

The following data formats are supported

ü SEG-Y – IBM-FLOAT-32 samples

ü SEG-Y – IEEE-FLOAT-32 samples

ü CWP/SU

Save trace(s) sample values to text file

Procedure is same as for Saving SEG-Y file, except you need to set “Трасе Samples Text File” file type.

Export trace headers values to the text file

To export select the following menu items:

“File” ® “Export Trace Headers to ASCII file”

Check “Write Column info” if column information is needed.

Press “Save” to start export. Header values that are selected in the “Trace Headers” window will be exported to output file.

Here is scructutre of the output file:

P 0 F 0 Trace index in file

P 9 F 4 * FFID - Original field record number

P 17 F 4 SP - Energy source point number

P 21 F 4 CDP ensemble number

P237 F14 New Item 1

EXPR SP from CDP =

+----------+----------+----------+----------+----------+----------

1 858 1100 1519 0.25 860

2 858 1100 1520 0.5 860.5

3 858 1100 1521 0.75 861

4 858 1100 1522 1 861.5

5 858 1100 1523 1.25 862

6 858 1100 1524 1.5 862.5

At the beginning of the file column information will be recorded

(if “Write Column Info” is checked):

Position	Contents	Description
1 - 4	Pnnn or EXPR	nnn – number that shows byte position of header item if value is expression
5	space
6 - 8	Fnn or three spaces	nn – число, соответствующее номеру формата if value is expression
9	space
10 -	text	header item description

The next line is column info terminator – line that starts with “+” character.

Header item values will be placed after this line

First column contains ordinal number of the trace (as it is in file, starting from 1). The following columns contain header values.

Import trace header values from text file

File to be imported should be in the same format as exported file.

To import header values from file select the following menu:

“File” ® “Import Trace Headers from ASCII file”

Press “Load” to start import.

Select input file and press “Open”

Toggling “Apply Delay Recording Time” mode

Sometimes time of first trace sample is defined by “Delay Recording Time” trace header value. It is necessary to switch-on “Apply Recording Delay Header” to display seismic line with such traces properly. While working in this mode you can note some file opening delay, especially if file size if big. If you are sure that traces in current file are not shifted than you can toggle this mode off.

To toggle the mode select “File” ® “Apply Recording Delay Header” menu item or set check to .

Display mode selection.

“Display mode” and “Wiggle Fill” panels

The modes and corresponding controls’ positions are shown in the following table

	Mode	Controls position	Seismic sample
1	Wiggle
2	Wiggle + Positive Fill (Variable area)
3	Wiggle + Negative Fill
4	Variable density (Gray levels)
5	Color
6	Color + Wiggle

Display Mode panel controls	Description
Wiggle	Wiggle mode
Gray	Variable density mode
Color	Color mode

Wiggle Fill panel controls	Description
None	No wiggle fill
Positive	Positive fill
Negative	Negative fill

“Colors” panel

Use this panel to select colors:

Colors panel controls	Description
Wiggle	Wiggle color
Fill	Fill color
Selected	Selected trace color

Color mode palette setup

Press button to popup “Palette” dialog.

The palette consists of color markers, space between two markers is filled by linear interpolation of color.

Originally the palette is made of three markers:

#	Marker	Description
1	-100%	Maximal negative amplitude value
2	0%	Zero amplitude level
3	+100%	Maximal positive amplitude value

To select a marker pick it by mouse in the “Markers/Levels” panel.

To choose new color for a marker, use panel of colors in the right part of the dialog. Selected color will be shown “Selected Color” field. To assign the color to the selected marker, press “Assign Color” button.

To add a new marker, press “Add Marker” button. New marker will be added between selected and previous markers.

To remove selected marker, press “Delete Marker” button.

Marker position can be changed by moving marker position control by mouse.

Created palette can be saved in the system registry. Enter the palette name in text field “Saved palettes” and press “Save” button.

To load any of previously saved palettes, select it in “Saved palettes” combo-box.

To remove current palette from registry press “Delete” button.

Press “Apply” button to apply current palette to the seismic window. “OK” button also applies palette and close the dialog. “Close” remove dialog window without any effect to seismic.

Scaling and gain setup

Scale panel

Scale panel controls	Description
Traces	Set trace number per centimeter
Time	Set time scale (cm/sec)
Gain-w	Wiggle Gain control
Gain-c	Color Gain control
=	Check this if you need same gain value for both modes

To adjust a value by mouse, move mouse cursor to the corresponding slider (), then press left mouse button, and (keeping it pressed) move the slider. Current value of the parameter will be shown in edit control that is on the right of the slider, and seismic image will be repainted to reflect the changes.

Direction panel

Direction panel control	Description
Normal	From left to right
Reversed	From right to left

Zoom buttons.

Button	Description
	Fit all the image to seismic window size
	Zoom by window. Press this button then draw a rectangle on the seismic window (move mouse cursor to first corner of the rectangle, press left mouse button, and keeping it pressed, move mouse to set desired size). Selected region will be zoomed to size of the seismic window.
	Return to previous zoom
	Zoom in (1.5 times)
	Zoom out (1.5 times)

Direction of scale changing caused by , , buttons depends on the following radio-buttons selection:

Button	Description
	Scale changes in both directions
	Scale changes in horizontal direction
	Scale changes in vertical direction

Automatic gain control button

After button is pressed, the program will adjust current wiggle gain, using maximal amplitude values of selected trace (see “Trace Selection article”).

To adjust color gain use button

Seismic window

To show this window select “Seismic” tab.

When you move mouse pointer in the seismic window, values corresponding current position will be shown in status bar at the bottom of the main window and in “Mouse Position Header Box”

Trc	Trace number in the file
Time	Time (ms)
Smp	Sample value (processing is applied!)

Axes labeling setup

Press button, to popup Axes dialog.

The dialog has two tabs. To select headers that should be shown on the top of seismic, click “Trace Axis (Headers)” tab.

There are two lists on this tab: "Selected Headers" list contains descriptions of trace header items that will be shown above seismic section, and "Available Headers" list contains all the SEG-Y trace header items.

Item order in "Selected Headers" corresponds to its position on axis (higher or lower)

Controls on "Trace Axis" tab:

Control	Description
	Add selected header item from "Available Headers" to "Selected Headers" list
	Remove selected header item from "Selected Headers" list
	Clear "Selected Headers" list
	Move selected header item in "Selected Headers" Up
	Move selected header item in "Selected Headers" Down

For each item in "Selected Headers" you can specify start value and step. For example: Select "CDP ensemble number” item, assign start value=10 and step=10 to it. In this case traces with CDP numbers = 10, 110, 210, etc will be labeled.

To setup time axis labeling step click “Time Axis” tab.

Enter the step value. If time lines are needed set mark in the “Timelines” checkbox.

To accept the changes press “Apply” or “OK” button. “OK” also closes the dialog. “Close” button discards any changes and closes the dialog.

Scrolling the seismic image

There are two ways to scroll the image:

- using scroll bars

- dragging by mouse

Move mouse cursor to start point, then press left mouse button and keeping it pressed, move the image into desired direction.

Trace selection

To switch into selection mode press button. It is the same button that is used to switch into “Pan” mode. Image on button, depict mode that will be selected after the button press.

While selection mode is chosen, move mouse cursor to desired trace and press left mouse button. As result, this trace becomes “selected”.

Trace header values of the selected trace will be shown in “Bin header” panel (see “Display headers” article).

This trace is also used for automatic gain control.

To move trace selection some number traces forward or backward use the following controls:

Fill edit control with move step value

Press button to move forward, and to move backward

Display, edit headers and data

After button is pressed, “Headers” panel will be shown in the left part of the seismic window:

Contents of the panel depend on which radio-button is checked.

Button	Contents
General	General file information
Trace header	Header of the selected trace
Bin header	Binary header of SEG-Y file
Text header	Text header of SEG-Y file
Trace data	Trace data sample values

To change the panel size, move mouse cursor to the right boundary. And when the mouse cursor is changed into , press left mouse button, and holding it pressed move panel boundary into desired direction.

Trace header items browsing

Press “Trace Header” button to show contents of the selected trace header:

Besides browsing of known header items (“Items” tab), it is also possible to display trace header as dump of integer values array for nonstandard data analysis (“Dump” tab).

SEG-Y file text header editing[3]

Press “Text Header” button to show contents of the text header.

Select appropriate line of the header by mouse then enter changes from keyboard.

To save the changes press “Update” button, or press “Reset” button to undo all the changes[4].

It is also possible to load text header data from text (ASCII) file. To do this press “From file” button or select menu “File” ® “Load Text Header from File”. To load the data from the previous file, press small button that is on the right of the “From file” button.

To save the header into text (ASCII) file select “File” ® “Save Text Header to File” menu item.

SEG-Y file binary header editing[5]

Press “Bin Header” button to show contents of the text header.

Select appropriate line of the header by mouse then enter changes from keyboard. “Sample Interval”, “Number samples per data trace for reel” and “Data Sample Code” items cannot be changed because they affect to file integrity. If you need nevertheless to edit these items, then check “Allow to edit all items” box.

Modified lines are highlighted by blue color. Bad values are marked by red.

Program will not update file till all the bad values are corrected.

To save the changes press “Update” button, or press “Reset” button to undo all the changes[6].

Trace Headers window

Header Items browsing

To show this window select “Trace Headers” and “View” tabs.

Check items in Selection panel that you want to display. Values of selected header items will be shown in Data panel.

Pressing to button selects all the items, and clears all selection.

The program checks for trace headers consistence. If current trace header value difference with previous trace header is not equal difference with next trace, this value is highlighted by red color.

Custom header items creation

The program allows create custom header item description. Use control panel buttons for this.

The button creates a new header and shows editing dialog window

The button shows editing dialog window for current header item

The button removes the current item

Note: you can edit only custom header items.

There are two types of items:

positional: 16 or 32-bit integer, from arbitrary header position

computable: its value is calculated by mathematical expression

In case of positional item we have the following dialog:

Fields:

Name	Item name: it should be unique, it will be used for header axis labeling in seismic window and for table column labeling in the trace header window
Description	Header item description
Position	Byte position (from 1) for this item in trace header
Format	Select needed format from combo box: Integer1,2,4, IEEE Float4,8, IBM Float4

You can copy position and format from existing item to “Position” и “Format” fields. To do this, select item in “Available Headers” list and press button.

To create a computable item select “Expression” tab

Enter an expression that consists from numbers, parenthesizes, operators (+-/*) and special variables

Examples:

Expression	Description
N	- current trace number in the file
N*2	- same multiplied by 2
2	- just value 2
H(21,4)*2	- integer*4 from position 21 of trace header (CDP) multiplied by2

Тrace Searching

Go to end or beginning of the file

- go to the first trace
- go to the last trace

Go to the trace with given index

To activate this mode click left mouse button over “Trace #” table header

Fill in search number (N)

Select search condition from the list:

= go to trace index of which is equal of the search number
+ go N traces forward
- go N trace backward

Trace search by header item value

To activate this mode click left mouse button over needed header item name

(like “CDP”)

Fill in search number (N)

Select search condition from the list:

= find trace where selected header item value is equal N
+ find trace where selected header item value is equal current value + N
- find trace where selected header item value is equal current value - N
≠ find trace where selected header item value is not equal N

Press one of the following buttons:

- sequential search forward

- sequential search backward
- fast binary search[7], it works only on ordered sequence of values (ascended or descended) (≠ is not supported)

If file size is big, then search may take sufficient amount of time.

Press button to terminate current search.

Trace header editing

Single trace header item modification

Move mouse pointer to table cell with header item value that you are going to change and press left mouse button.

Name and value of selected item will be shown on screen

Fill in edit field by new item value

and press Update button

Trace headers changing by expression

Headers of selected traces (See: “Selection of traces to be displayed” article) can be changed by means mathematical expressions.

To activate modification window select “Trace Headers” and “Change” tabs.

Check header to be changed in the selection panel, then in data panel click table header corresponding to it in the data panel:

Then fill in “Expression” field with expression text.

The following variables have a special meaning:

Variable	Description
N	Ordinal trace number in SEG-Y file
L	Last trace number in SEG-Y file

Function that returns arbitrary trace header item value is also defined:

Н(p,f), where p – item position in the header, f – format (2-integer*2, 4-integer*4)

For example: H(21,4) returns CDP number.

Toolbar buttons:

Inserts value of item currently selected in the selection panel

Inserts current trace number in the expression

Insert last trace number

Clears expression field

Update file with new values

Undo the latest file modification

Repeat all above for each item you want to change and then press button.

The following dialog will be shown:

Press “Update” to change file or “Close” to cancel changes.

Hardcopy window

To show this window select “Hardcopy” tab.

Печать изображения

To print seismic image select “Print” tab.

Press “Setup” button to choose printer and page size. Standard “Print setup” dialog will be shown. Use it to setup your parameters. Information about selected printer will be shown in “Printer Info” panel.

To select orientation of plot use “Horizontal” and “Vertical” radio-buttons.

It is possible only part of seismic section, for that you need to fill in Print Region form:

Tmin	Minimal Time (ms)
Tmax	Maximal Time (ms)
From tr.	Start from this trace
То tr.	Stop at this trace

Use “min” and “max” buttons to set minimal or maximal possible values.

To place text label (one string) from “Label” edit control to printout set mark into checkbox. “File name” button puts current file name into edit control, and “Clear” button empties the control.

If image size is bigger then page size then it will be spitted into several parts.

Print preview panel shows as image is divided into pages. If you changed display mode, scaling, etc, then current changes also will be reflected in the preview panel.

To print the image, press “Print” button. The button label changes to “Abort Print”. Printing progress will be shown in progress bar at the bottom of the window..

To cancel printing, press “Abort Print” button.

While printing other work with the program is not allowed.

Экспорт изображения сейсмики в формате Windows Bitmap (.bmp)

Select “Export” tab in “Hardcopy” window

Fill “Bitmap Dpi” field with "dot per inch" value for your bitmap image

In “Color Mode” select image type: 256-color (color 8-bit) or black and white (b/w -1 bit).

Then press “Export” button. When standard “File Save” dialog appears, use it to specify output file. “Close” button discards dialog.

Processing

Processing is applied to trace before it will be shown on screen. Here is the processing modules list:

- band pass filter

- automatic gain control (AGC)

- data inversion (negation)

Processing parameters setup

To set the processing parameters press button or select “Processing” ® “Parameters” menu item, after that “Processing” dialog appears. Enter parameters needed. To accept the parameters press “Apply” or “OK” button. “OK” also closes the dialog. “Close” button discards any changes and closes the dialog.

Processing panel

Use the panel to toggle corresponding processing.

Processing panel item	Description
Inversion	Data inversion (Negation)
Filter	Band pass filter
Agc	Automatic gain control
Weight	Use Trace Weighting Factor trace header item

Band pass filter

Enter filter cut frequencies as it is shown in the picture and check “Use filter”, if you want to use the filter.

Original data	Filtered data

Automatic gain control (AGC)

“Window length” parameter sets AGC window length. AGC module moves the window down the trace sample-by-sample and calculates a scale factor at each location. The scale factor is equal to the RMS amplitude in the window.

Enter “Window length” and check “Use AGC”, if you want to use the AGC.

Original data	AGC applied

Inversion

This module replaces each sample in trace to inversed value (multiply by minus one).

Check “Use Inversion” to apply the inversion.

Appendices

Expressions

Special variables and header item value function

The following variables have a special meaning:

Variable	Description
N	Ordinal trace number in SEG-Y file
L	Last trace number in SEG-Y file

Function that returns arbitrary trace header item value is also defined:

Н(p,f), where p – item position in the header, f – format (2-integer*2, 4-integer*4)

For example: H(21,4) returns CDP number.

Expression Syntax

Expressions have pretty much the same syntax as they would have on paper, with the following exceptions:

Each expression must end with a semicolon. This is because the expression string can actually contain multiple expressions. The semicolon is used to mark the end of the expression. In our case semicolon at the end of the expression can be omitted.

Examples:

4*x+5;
y=5+2;g=4+6;
y=r*sin(a);x=r*cos(a);

The asterisk '*' must be used to multiply.
Examples:

y=5*6; Valid
g=(x+1)*(x-1); Valid
g=(x+1)(x-1); Invalid

More than one expression may be contained within an expression string. As shown above, each expression must end with a semicolon, even if only one expression is in the string. The value of an expression string is the value of the last expression in the string.
Examlples:

g=7; Value: 7
k=z+1; Value: z+1
r=4;k=6;o=9+r-k; Value: 9+r-k

Some functions may take reference parameters. These parameters are references to other variables. You can mix reference parameters with normal parameters. The order of the normal parameters must remain the same and the order of the reference parameters must remain the same.
Examples:

min(1,2,3,4,&mval); &mval is a reference to a variable mval
min(1,2,&mval,3,4); You may mix them inside like this.
min(1,2,(&mval),3,4); You may not nest reference parameters in any way

Expressions may also be nested with parenthesis.
Examples:

y=sin(x-cos(5+max(4,5,6*x)));
6+(5-2*(x+y));

Expressions may also have whitespace characters and comments. Whitespace characters such as newlines, linefeeds, carriage returns, spaces, and tabs are ignored. Comments begin with the less than-sign '<' and end with the greater than-sign '>'. Comments may be nested as well.

Example:

<Set the x value>

x = d * cos(r);

<Set the y value>

y = d * sin(r);

<Comment out this for now

<Flip the values>

t = x;

x = y;

y = x;

Stop commenting out>

If a variable is used in an expression, but that variable does not exist, it is considered zero. If it does exist then its value is used instead.

ExprEval Internal Functions (by Brian A. Vanderburg II)

The following functions are provided with ExprEval:

Function	Min. Args	Max. Args	Min. Ref Args	Max. Ref Args	Result/Comment
abs(v)	1	1	0	0	Absolute value of v. abs(-4.3) returns 4.3
mod(v,d)	2	2	0	0	Remainder of v/d. mod(5.2,2.5) return 0.2
ipart(v)	1	1	0	0	The integer part of v. ipart(3.2) returns 3
fpart(v)	1	1	0	0	The fractional part of v. fpart(3.2) returns 0.2
min(v,...)	1	None	0	0	The minimum number passed. min(3,2,-5,-2,7) returns -5
max(v,...)	1	None	0	0	The maximum number passed. max(3,2,-5,-2,7) returns 7
pow(a,b)	2	2	0	0	The value a raised to the power b. pow(3.2,1.7) returns 3.2^1.7
sqrt(a)	1	1	0	0	The square root of a. sqrt(16) returns 4
sin(a)	1	1	0	0	The sine of a radians. sin(1.5) returns around 0.997
sinh(a)	1	1	0	0	The hyperbolic sine of a. sinh(1.5) returns around 2.129
asin(a)	1	1	0	0	The arc-sine of a in radians. asin(0.5) returns around 0.524
cos(a)	1	1	0	0	The cosine of a radians. cos(1.5) returns around 0.0707
cosh(a)	1	1	0	0	The hyperbolic cosine of a. cosh(1.5) returns around 2.352
acos(a)	1	1	0	0	The arc-cosine of a in radians. acos(0.5) returns around 1.047
tan(a)	1	1	0	0	The tangent of a radians. tan(1.5) returns around 14.101
tanh(a)	1	1	0	0	The hyperbolic tangent of a. tanh(1.5) returns around 0.905
atan(a)	1	1	0	0	The arc-tangent of a in radians. atan(0.3) returns about 0.291
atan2(y,x)	2	2	0	0	The arc-tangent of y/x, with quadrant correction. atan2(4,3) returns about 0.927
log(a)	1	1	0	0	The base 10 logarithm of a. log(100) returns 2
pow10(a)	1	1	0	0	10 raised to the power of a. pow10(2) returns 100
ln(a)	1	1	0	0	The base e logarithm of a. ln(2.8) returns around 1.030
exp(a)	1	1	0	0	e raised to the power of a. exp(2) returns around 7.389
logn(a,b)	2	2	0	0	The base b logarithm of a. logn(16,2) returns 4
ceil(a)	1	1	0	0	Rounds a up to the nearest integer. ceil(3.2) returns 4
floor(a)	1	1	0	0	Rounds a down to the nearest integer. floor(3.2) returns 3
rand()	0	0	0	0	Returns a number between 0 up to but not including 1.
random(a,b)	2	2	0	0	Returns a number between a up to and including b.
srand(a)	1	1	0	0	Seeds the random number generator with a value. Return value is unknown
randomize()	0	0	0	0	Seed the random number generator with a value based on the current time. Return value is unknown
deg(a)	1	1	0	0	Returns a radians converted to degrees. deg(3.14) returns around 179.909
rad(a)	1	1	0	0	Returns a degrees converted to radians. rad(180) returns around 3.142
recttopolr(x,y)	2	2	0	0	Returns the polar radius of the rectangular co-ordinates. recttopolr(2,3) returns around 3.606
recttopola(x,y)	2	2	0	0	Returns the polar angle (0...2PI) in radians of the rectangular co-ordinates. recttopola(2,3) returns around 0.588
poltorectx(r,a)	2	2	0	0	Returns the x rectangular co-ordinate of the polar co-ordinates. poltorectx(3,1.5) returns around 0.212
poltorecty(r,a)	2	2	0	0	Returns the y rectangular co-ordinate of the polar co-ordinates. poltorecty(3,1.5) returns around 2.992
if(c,t,f)	3	3	0	0	Evaluates and returns t if c is not 0.0. Else evaluates and returns f. if(0.1,2.1,3.9) returns 2.1
select(c,n,z[,p])	3	4	0	0	Returns n if c is less than 0.0. Returns z if c is 0.0. If c is greater than 0.0 and only three arguments were passed, returns z. If c is greater than 0.0 and four arguments were passed, return p. select(3,1,4,5) returns 5
equal(a,b)	2	2	0	0	Returns 1.0 if a is equal to b. Else returns 0.0 equal(3,2) returns 0.0
above(a,b)	2	2	0	0	Returns 1.0 if a is above b. Else returns 0.0 above(3,2) returns 1.0
below(a,b)	2	2	0	0	Returns 1.0 if a is below b. Else returns 0.0 below(3,2) returns 0.0
avg(a,...)	1	None	0	0	Returns the average of the values passed. avg(3,3,6) returns 4
clip(v,min,max)	3	3	0	0	Clips v to the range from min to max. If v is less than min, it returns min. If v is greater than max it returns max. Otherwise it returns v. clip(3,1,2) returns 2
clamp(v,min,max)	3	3	0	0	Clamps v to the range from min to max, looping if needed. clamp(8.2,1.3,4.7) returns 1.4
pntchange(side1old, side2old, side1new, side2new, oldpnt)	5	5	0	0	This is used to translate points from different scale. It works no matter the orientation as long as the sides are lined up correctly. pntchange(-1,1,0,480,-0.5) returns 120 (x example) pntchange(-1,1,480,0,-0.5) returns 360 (y example)
poly(x,c1,...)	2	None	0	0	This function calculates the polynomial. x is the value to use in the polynomial. c1 and on are the coefficients. poly(4,6,9,3,1,4) returns 2168 same as 64⁴ + 94³ + 34² + 14¹ + 4*4⁰
and(a,b)	2	2	0	0	Returns 0.0 if either a or b are 0.0 Else returns 1.0 and(2.1,0.0) returns 0.0
or(a,b)	2	2	0	0	Returns 0.0 if both a and b are 0.0 Else returns 1.0 or(2.1,0.0) returns 1.0
not(a)	1	1	0	0	Returns 1.0 if a is 0.0 Else returns 0.0 not(0.3) returns 0.0
for(init,test,inc,a1,...)	4	None	0	0	This function acts like a for loop in C. First init is evaluated. Then test is evaluated. As long as the test is not 0.0, the action statements (a1 to an) are evaluated, the inc statement is evaluated, and the test is evaluated again. The result is the result of the final action statement. for(x=0,below(x,11),x=x+1,y=y+x) returns 55.0 (if y was initially 0.0)
many(expr,...)	1	None	0	0	This function treats many subexpressions as a single object (function). It is mainly for the 'for' function. for(many(j=5,k=1),above(j*k,0.001),many(j=j+5,k=k/2),0)

ExprEval Internal Constants

The following constants are provided with ExprEval:

Constant	Math Form	Value
M_E	e	2.7182818284590452354
M_LOG2E	log₂(e)	1.4426950408889634074
M_LOG10E	log₁₀(e)	0.43429448190325182765
M_LN2	ln(2)	0.69314718055994530942
M_LN10	ln(10)	2.30258509299404568402
M_PI	π	3.14159265358979323846
M_PI_2	π/2	1.57079632679489661923
M_PI_4	π/4	0.78539816339744830962
M_1_PI	1/π	0.31830988618379067154
M_2_PI	2/π	0.63661977236758134308
M_1_SQRTPI	1/√(π)	0.56418958354776
M_2_SQRTPI	2/√(π)	1.12837916709551257390
M_SQRT2	√(2)	1.41421356237309504880
M_1_SQRT2	1/√(2)	0.70710678118654752440

Application Internal Functions

Application defined expression functions go here.

Function	Min. Args	Max. Args	Min. Ref Args	Max. Ref Args	Result/Comment

Application Internal Constants

Application defined expression constants go here.

Constant	Math Form	Value

Application Internal Variables

Application defined expression variables go here.

Variable	Math Form	Value

Trace value, gain and view on screen

When gain = 1 sample value of +1 is in the center of the next trace, and –1 in the center of previous one.

This example shows drawing of sine trace with amplitude 1.0

Gain=1.0

Gain=0.5

For color mode we calculate value from Sample_Value*Gain*100 and select color from palette (top -100, bottom +100)

The same traces in color coding:

Gain=0.5

Gain=1.0

Simplified SEG-Y file structure

File headers

Seismic traces

3200 bytes

text header (EBCDIC)

400 bytes binary header

240 bytes trace header

seismic trace data

240 bytes trace header

seismic trace data

240 bytes trace header

seismic trace data

Details are here SEG (Society of Exploration Geophysicists):

http://www.seg.org/publications/tech-stand

Yuzhno-Sakhalinsk

Russia

2004

[1] Sorry people, English is not my native language.

[2] The program supports the same sample formats that can be produced by “ProMAX” Seg-Y output module.

[3] You cannot edit the header if file has read-only attribute.

[4] “Reset” and “Update” buttons affects to text and binary header at the same time.

[5] You cannot edit the header if file has read-only attribute.

[6] “Reset” and “Update” buttons affects to text and binary header at the same time.

[7] A fast way to search a sorted array is to use a binary search. The idea is to look at the element in the middle. If the key is equal to that, the search is finished. If the key is less than the middle element, do a binary search on the first half. If it's greater, do a binary search of the second half.

Toggling “Apply Delay Recording Time” mode

Direction panel

Button

Trace header items browsing

SEG-Y file text header editing[3]

SEG-Y file binary header editing[5]

Go to end or beginning of the file

Go to the trace with given index

Trace search by header item value

Печать изображения

Экспорт изображения сейсмики в формате Windows Bitmap (.bmp)

Processing panel

ExprEval Internal Functions (by Brian A. Vanderburg II)