Pviewer - A Packaged Array Data Viewer Written in Python Language

Ben-chin K Cha
Timothy Mooney
Maintained by Ben-chin Cha ([email protected])


Pviewer python package is an EPICS extensions tool specially written for displaying any ASCII or MDA data file. Where ASCII files can be any column oriented data file created by report generation by any tools, and MDA data is automatically saved scan file by IOC. The common shared routines for image or data processing are implemented such that they can be re-used by any other python programs.

The complete package consists of following python modules:

    MDA data process: 	readMDA.py
    Image process: 	view2d.py

    Line plot program: 	plotAscii.py
    Pviewer package: 	pviewer.py

    matplotlib package: plot1d.py

    3D graphic package: 3dgraph.py

The original readMDA.py is implemented by Tim Mooney and it provides the MDA reader routine to extract scan data from MDA files. Please refer the Functions section in readMDA.html for available routines defined in this module. The original version of mdaAscii.py is obtained from Tim Mooney, it had been extensively modified and now it supports various types of 1D/2D report generations. Please refer the Functions section in mdaAscii.html for available routines defined in this module. The plot.py is implemented by Tim Mooney which is able to display any 4 detector array from the current scan record specified by user. Please refer the python applications for beamline control implemented by Tim Mooney for details.

The multi-line plot package plotAscii.py is based on the graph classes from graph.py which is extracted and modified from Grayson's book. It accepts Ascii text file on the command line, and also provides simple widgets to let user easily tailor the final multi-line plot. Please refer the Functions section in plotAscii.html for available routines defined in this module.

The 2D image features in imageUtil.py and view2d.py are developed based on the Image classes from the Python Image Library. It provides easy to use routines to display scientific data or any picture files. Please refer the Functions section in imageUtil.html and view2d.html for examples on image processing routines.

On top of common shared routines, the pviewer is designed with the goal that it provide flexible user interface to access ASCII/MDA data and display 1D/2D data graphically. It also provide convenient menu to access any system command and to access IDLVM scan tools like scanSee / catcher / mca supported by BCDA.

The GUI in pviewer.py is implemented based on the basic classes AppShell and ProgressBar developped by John E. Grayson from the book of Python and Tkinter Programming (Ref.1). It integrates the multi-line plots, image processing, MDA reader, MDA report generation all into one system. So user can access and display any 1D/2D data array from ASCII or MDA files.

The GUI tv.py program can display any picture file or display any real ASCII 2D data array as image with a set of user selectable color tables. It is built from the imageUtil.py and the scrapbook class extracted and modified from Grayson's book. Please refer tv.html for more information about this program.

Currently the complete set of programs had been successfully tested on both UNIX, LINUX and WIN system.


pviewer.zip - Download complete set of pviewer python programs

System Requirement

Python System Requirement

The python operating system should also include the following module library:
	Tkinter - Tk interface library
	Pmw - python mega widget library
	PIL - python image library
	Numeric  - python numeric package

System Setup Requirement

The python setup requirement for oxygen user just enter:
	source ~cha/setup_python
The contents of ~cha/setup_python is given below:
  setenv PYTHONSTARTUP /home/oxygen/CHA/epics/extensions/lang/python
  setenv PYTHONPATH .:/opt/local/lib:/home/oxygen/CHA/epics/extensions/lang/python:/home/oxygen/CHA/epics/extensions/lib/solaris-sparc
  set path=(~cha/epics/extensions/bin/solaris-sparc ~cha/epics/extensions/lang/python $path) 

How to Start/Stop Python Program ?

To invoke python on Unix command line:
Normally exit python program by entering CNTL-D at the python prompt >>>. Python session may also be aborted by entering CNTL-\ at the python prompt >>> in this case a core file will be created.

Access readMDA.py Routines

There are two ways of accessing MDA scan data file: using file selection dialog to pick the file, or using the known file name directly .

pickMDA routine

For an example of using file selection dialog to pick an desired MDA file, and return the scan data structure d
	from readMDA import *
	d = pickMDA()

readMDA routine

For an example of passing a known MDA file name, and return the scan data structure d
	from readMDA import *
	d = readMDA('/home/beams/CHA/data/xxx/cha_0001.mda')

Access mdaAscii.py Routines

Currently avaialbe ASCII report generation functions for MDA file include the following:
	mdaAscii_1D - generate report from multi-detector 1D array
	mdaAscii_2D - generate seperate 2D report for each defined detector 
 	mdaAscii_2D1D - generate 1D report from multi-detector 2D image array
	mdaAscii_IGOR - generate all detector 2D images in a single IGOR file
	mdaAscii_all - automatically generate 1D/2D ascii reports for each mda
		       file from the specified mda data directory path
Please refer the Functions section in mdatAscii.html for informaion of routine command syntax.

For an example of generating separate 2D ASCII image report for every defined detector found in a 2D/3D MDA scan file.

	from mdaAscii import *
	d = readMDA(filename)
	fn = mdaAscii_2D(d)

For an example of generating 2D images of all defined detectors found in a 2D/3D MDA scan file as a single IGOR file.

	from mdaAscii import *
	d = readMDA(filename)
	fn = mdaAscii_IGOR(d)

Access plotAscii.py Routines

Two types of text file can be passed to plotAscii.py program: column or row oriented text file. Text lines start with '#' or ';' will be treated as comment lines. For column oriented file each data line should contain same number of columns. It may contain X column vector in column vector array.

Column Oriented Text File

For an example the typical scan report generation file ASCII/cha_0015.1d.txt, the first (0) column contains the X values, remaining 8 columns contain the detector vector values. To access the multi-line plotter plotAscii.py on the Unix system, at Unix prompt just enter
	plotAscii.py ASCII/cha_0015.1d.txt 0
For the case there is no X column defined in the text file -1 instead of 0 should be used. The plotAscii.py is a GUI program, by default it plots the first two curves. After modify the plot by Symbol, Legend, Toggle buttons, and Title... widgets, the final plot is show below.

Row Oriented Text File

For scattering line plot, the row oriented text file should be used. Each set of data curve should contain two lines: first line for X values and second line for Y values. Different set of curves may contain different X values or different number of data points. For an example 'pts.txt' given below :
# pts.txt Example of row oriented scattering text data
# line 1
1. 2. 3.  4.  5.
1. 4. 9. 15. 25.
# line 2
 1.  2.  3.  4.  5.  6.  7.  8.  9. 10.
11. 12. 13. 14. 15. 16. 17. 18. 19. 20.
To pass 'pts.txt' to plotAscii.py on the Unix system:
	plotAscii.py pts.txt
The plot result with symbol is given below:

Files Used

Files used by plotAscii.py include following:
	SH 	       - shared dictionary use to set printer, X column, etc 
	pvs            - shared text file holds the list of legends
	*.txt	       - any 1D/2D text data file 

plotAscii User Interface

	Data...         - scroll text window to display data columns
	Transpose...    - transpose row data into column data and saved in '1.txt'
			  and submit a new plotAscii.py with the transposed file 
	Legend...       - dialog to modify legend for data column 
	LegendLoc...    - dialog to set relative legend location on plot 
	XRange...       - dialog to set X range of start/end points for plot
	Symbol          - check button for plot symbol on or off
	Legend          - check button for plot legend on or off
	Graph		- plot drawing area
	CB group	- check buttons for marking plotted curves 
	All On          - plot all curves 
	All Off         - none curve selected
	Clear           - Clear plot area
	Redraw          - redraw the plot area
	Printer...      - dialog to set printer 
	Print		- send the plot to printer
	Title...        - dialog to change plot title, xtitle 
	Quit            - exit the plotAscii program

Access imageUtil.py Routines

Please refer the Functions section in imageUtil.html for other image processing routines not covered in this section.

Available Color Tables

There are 41 color tables defined in the file CT. These set of color tables can be used to display scientific data image. A user can load any desired color table from the CT by calling readCT() function from imageUtil.py,e.g.
	from imageUtil import *
	ct = readCT(i)		# i specify color table sequence number 
The list of color table defined in CT is given below:
	Seq#	Color Table Description
         6 	PRISM
        12 	16-LEVEL
	13      RAINBOW
	14      STEPS
        15 	STERN SPECIAL
	16 	Haze
	17 	Blue-Pastel-Red
        18 	Pastels
	19 	Hue Sat Lightness1
	20      Hue Sat Lightness2
        21 	Hue Sat Value 1
	22      Hue Sat Value 2
	23 	Purple-Red + Stripes
        24 	Beach
	25 	Mac Style
	26 	Eos A
        27 	Eos B
	28 	Hardcandy
	29 	Nature
        30 	Ocean
	31 	Peppermint
	32 	Plasma
        33 	Blue-Red
	34 	Rainbow
        35 	Blue Waves
	36      Volcano
	37 	Waves
        38 	Rainbow18
	39 	Rainbow + white
	40 	Rainbow + black
At the end of readCT(), the temporary file 'pal.dat' will be updated to hold the current color table picked by user. The image data displayed will be scaled with the color table picked by user.

Access display2D Image routine

Example of displaying 2D data as an TV image is given below, in this case the image text file ASCII/2idd_0087.D12.txt was previously created by MDA report generation in pviewer.py:
	from plotAscii import readArray
	from imageUtil import *
	ct = readCT()		# load rainbow+white color table 
	da = readArray('ASCII/2idd_0087.D12.txt')
	im = display2D(da,1)

	ct = readCT(3)		# load red temperature color table
 	im = display2D(da,1)

Access view2d.py Routines

Please refer the Functions section in view2d.html for other image processing routines not covered in this section.

Example of extracting a 2D image from an MDA 2D scan file.

	from view2d import *
	file ='/home/beams/CHA/Yorick/data/2idd_0087.mda'
	ct = readCT()		# load the rainbow+white(40th) color table
				# ct = readCT(0) load black/white color table
	d = panMDA(file)	# readMDA and pan all images

	from view2d import *
	file ='/home/beams/CHA/Yorick/data/2idd_0087.mda'
	d = readMDA(file)
	pick2d(d,14,updown=1)		# plot the 15th image upside down

As show in this rainbow + white color table, the place where the maximum value occurs is displayed as white color.

Access pviewer.py Program

The pviewer.py is a python application built on top of plotAscii.py, imageUtil.py, and view2d.py. It is a complete mouse driven GUI application. It is able to read and display any 1D/2D array from ASCII and MDA 1D/2D/3D data file. It provides multi-line plot for 1D array and image plot of 2D array. It also provides powerful MDA 1D/2D reports generation. Be aware that the reading of very large 2D/3D scan of 85 detectors MDA file may takes longer time.

To access the python program pviewer.py on the Unix system, at Unix prompt just enter


Pviewer Used Files

Various files used or created by pviewer.py include following:
	pviewer.config - configuration file saved for easy restart
	SH 	       - shared dictionary use by pviewer package
	CT	       - master array for 41 color tables
	pal.dat	       - extracted current color table 
	pvs            - text file holds list of legends for multi-line plot
	*.ppm,*gif,*png- various intermediate image files created 
	*.txt          - various text file created by report menu
	*.mda          - IOC autosaved MDA scan files 

Pviewer User Interface

The top level user interface is implemented by using the AppShell class from the Ref.1 in Python/Tkinter programming. Any button end with '...' implies that there is/are windows associated with it. The file selection dialog provides the user with flexible file selection user interface. The pviewer.config file is used to record the last ASCII and MDA data directories used for easy restart of the pviewer.py program.

The report generation features will create various type of 1D/2D reports under the sub-directory ASCII in the current working directory. User must have the write permission at the startup directory in order to be able to run this program.

Various dialogs for setting X,Y range or name legend are available for freely tailoring the graphic output.

Pviewer Main Window

The main window consists of the menubar area, the main display area for scroll text or scroll list dialog or opened MDA file detector information, and the message help bar area at bottom . As show below the main display area contains the text data from a 1D text file which was previously created by MDAReport->MDA 1D/2D Report....

File Menu
    Quit            Save 'pviewer.config' file and exit the pviewer application
    Printer...      Dialog to set up printer and update shared file SH
    Open Ascii...   Select the desired ASCII file and display the text
                    content in the scrolled main window
    Open MDA...     Select the desired MDA file and display the defined
                    detectors info in the main scrolled window
Setup Munu
    Color Table...       Dialog to display and select the desired color table, 
                         default is item 39 Rainbow + white, temporary file 
                         'pal.dat' is used to store the selected color table
    Name Legend...       Dialog to modify the legend name to be used in 
	                 multi-line plot.
    Image Upside Down    Checkbutton to plot image upside down

MDAView Menu
    Multi-line 1D Plot... Display MDA 1D report in main scrolled text window 
        		  area and pass it to 'plotAscii.py' sub-program
    PanImages...          Pass MDA 2D image array to panimage plotter
    Pick Di Image...      Dialog to pick detector and pass image to plot2d routine

MDAReports Menu
    MDA 1D/2D Report...   Generate MDA 1D/2D Ascii reports according to defined scan
                          and detectors and display the last generated file in the 
                          main scrolled text window 
    MDA 2D->1D Report...  Generate sequential MDA 1D Ascii report from 2D data array
                          and display the last generated file in the main 
                          scrolled text window 
    Generate All Report... Generate all 1D/2D reports for every MDA file found in the 
                          current MDA data directory 
    MDA to IGOR Report... Generate MDA 2D image report in IGOR format and display 
                          the file in main scrolled text window
    View ASCII Report...  Dialog to select report file and pop up text window to
			  display selected Ascii file 
    Remove All Report...  Dialog to remove all text file from current ASCII directory 

AsciiView Menu
    Multi-line Plotter..       Pass the Ascii data to multi-line plot program 
    Extract & Modify Legend... Dialog to extract legend from comment line if
                               defined in Ascii file
    TV Image ...               Display data as 300x300 colored scaled TV image

Ascii2Image Menu
    Plot2D...                   Pass 2D data directly to plot2d program
    X,Y Range for image...      Dialog set X,Y range and pass X,Y,Data to
                                plot2d program
    X,Y Line vector from mdaAscii file... 
			        Extracted X,Y vector from comment lines
                                from image text file generated by pviewer 
                                and pass X,Y,Data to plot2d program 
    Extract X,Y,DATA from scanSee Ascii file...
                                Extract X column, Y row, Data row & column
                                from scanSee/catcher/yviewer generated image
                                file and pass X,Y,Data to plot2d program

ScanTools Menu
    Python plot.py ... Run python program plot.py implemented by Tim Mooney
    idlvm sscan ...    Run scanSee program for IDLVM 6.0
    idlvm catcher ...  Run catcher program for IDLVM 6.0 
    idlvm mca ...      Run MCA program for IDLVM 6.0 

Tools Menu
    start_epics ...    Run the start_epics script
    Command Dialog...  Dialog for entering any valid system command or tools

Help Menu
    About...            Show pviewer program info
    Balloon Help        Toggle balloon help on or off
    pviewer_help.txt... Show this on-line help message

Message Bar Area:
    Balloon Message Area
    Progress Bar Area 	

Access tv.py Program

The python program tv.py provides python user with an easy to use GUI in displaying images and sending output to a printer. It can display any picture files with file type of JPEG, PNG, GIF, PPM. It also can display any real scientific 2D ASCII data as a linear scaled colored image. A collection of 41 color tables is available to pick in displaying the scientific image data. To access it just enter the following from Unix prompt.

Files Used

Various files used or created by tv.py include following:
	SH 	       - shared dictionary use by pviewer package
	CT	       - master array for 41 color tables
	pal.dat	       - extracted current color table 
	*.ppm,*gif,*png- various intermediate image files created 
	*.txt          - various text file created by report menu

Tv Main Window User Interface

Main window is an AppShell application with top menu bar, image displaying area, command control area, and message bar area.
    File Menu 
	Open Ascii Data...  - dialog to select 2D data file and display
	Picture Files...    - pop up picture browser dialog 
	Printer...	    - dialog to override default printer
	Print		    - send image to PS printer
	Close		    - exit the program
    Setup Menu
	Test indgen([30,20]) - display test data indgen([30,20]) as image
	Color Table...       - dialog to change color table to be used 
	Transpose Data Array - display the transposed data array 
	Flip image Upside/Down - flip and display image upside/down
	Flip image Left/Right  - flip and display image left/right
    Help Menu
	About...	- pop up program info 
	Booloon help    - check button for booloon help
    Drawing Area     - 300x300 pixel image display area
    Save As: 1.png   - field to specify the output picture file name to be saved, 
			  default 1.png 
    Raw Data         - check button display image as raw data size,	
			  default 300x300 pixels
    Command Area: 
	Save Image  - save the image to the output picture file
	Close       - exit the program
    Message Bar Area:
	Booloon Message Area
	Progress Bar Area 	

Ascii File Result

Following figure shows the result of File->Open Ascii Data... to open an ASCII 2D data texture file, the default color table of rainbow+white is used in scaling the data in this case.

Picture File Result

File->Picture Files... pops up the picture browser dialog to let user pick and display the desired picture file. Following figure shows the result of the picture browser with an opened picture file. Valid picture file includes jpeg, png, gif, ppm. Although the display image size is limit to 400x360 pixels, while the actual PS printer output will be the original raw picture size.

Please refer the tv.html for more information about tv.py.