Frequently Asked Questions


If you don't see an answer to your question here, send me mail.

Questions

  1. How do I graph more than 25 equations (why do my equations start to disappear after a while)?
  2. Can I specify piecewise-defined functions?
  3. How do I change the colors (how come it doesn't save my color choices)?
  4. How do I show trig functions in degrees instead of radians?
  5. Will there be a port to {Linux, Android, ...}?
  6. I'm getting errors when I use domains or initial values like {a:1,2,3}. Why?
  7. How do I draw a line [segment] between two points?
  8. How do I support separate configurations for multiple user accounts on a Windows XP machine? Or, why does Graphmatica complain on shutdown that it is unable to write to graphmat.ini?
  9. Can Graphmatica solve systems of inequalities?
  10. How do I view the help file on Vista?
  11. How do I perform a silent/unattended install on Windows?
  12. I am trying to print graphs along with equations formatted using the equation editor in Word 2007 (or 2010) on Windows XP (or 2003) and the equations don't print. What's wrong?
  13. Nothing happens (or, in newer versions, I get an error message pointing me here) when I try to paste a data plot from Excel. Why?

Answers

  1. How do I graph more than 25 equations (why do my equations start to disappear after a while)?
    The limit on the number of equations on-screen at once is there to help reduce the clutter after you've been drawing graphs for a while, but if you want to create graph documents with more equations than that, you can!
    1. Select Settings from the Options menu to bring up the Global Settings dialog box.
    2. Increase the number in the field marked "AutoRedraw On--Draw Last ___ equations" to anything up to 999.

  2. Can I specify piecewise-defined functions?
    Yes! In version 2.1, you can specify Cartesian and polar equations using multiple clauses with non-overlapping domains, separated by semicolons. For example:

    	y=-x {(,-1)} ; y=x^2 {[-1,1]} ;	y=2-x {(1,)}
    
  3. How do I change the colors (how come it doesn't save my color choices)?
    The color settings are now in the Colors tab of the Graph Paper settings dialog box (Options/Graph Paper). The documentation was corrected to reflect this in version 2.0b. All settings are saved automatically on exit in v2.0.

  4. How do I show trig functions in degrees instead of radians?
    The program doesn't really have a radians/degrees switch. But you can use the following approach to plot trig functions in degrees:
    1. Switch the range of the x axis to something appropriate for degree measure, e.g. -360 to 360.
    2. Multiply any references to the variable "x" or constants in degrees by the constant "d", e.g.
          y= cos (x*d-30d)
      
      will graph cosine with a 30 degree phase shift.

  5. Will there be a port to {Linux, Android, ...}?

    Linux users may want to try running the Win32 version on top of Wine (I've received several reports that it works just fine in that environment).

    I am investigating the possiblity of an Android port this summer, but I have not yet determined whether that's feasible. Still, I'm happy to take your name if you'd like to participate in testing it if/when it comes to fruition. If you are experienced in C coding for one of these platforms (or another favorite platform) and would like to partner with me on doing a port, please let me know.

  6. I'm getting errors when I use domains or initial values like {a:1,2,3}. Why?
    If your control panel settings specify that you use "," as the decimal separator, you need to be careful to use spaces between each value and the commas separating values, so they don't get confused with the commas serving as decimal points:
    	{a: 1, 2, 3}  NOT  {a:1,2,3}
    
  7. How do I draw a line [segment] between two points?
    Using the point-slope method, and a little pencil-and-paper arithmetic, it's quite easy to come up with the equation of a straight line between two points (x0, y0) and (x1, y1):
    	(x0-x1)y = (y0-y1)x + x0*y1 - x1*y0
    

    For example, the line between (1, 2) and (4, 3) would be given by the equation:

    	(1-4)y = (2-3)x + 1*3 - 4*2
    
    or, simplified,
    	3y = x + 5
    

    To draw a line segment instead of a line across the entire coordinate plane, simply add a domain bounded by the X coordinate of either endpoint:

    	(x0-x1)y = (y0-y1)x + x0*y1 - x1*y0 {x0, x1}
    
    (assumes x0 > x1; otherwise reverse domain)

  8. How do I support separate configurations for multiple user accounts on a Windows XP machine? Or, why does Graphmatica complain on shutdown that it is unable to write to graphmat.ini?
    As of version 2.0i, Graphmatica reads and writes graphmat.ini from your %APPDATA% directory, which is different for each user.
    In older versions, Graphmatica tries to save your current settings to the file graphmat.ini in the same folder as Graphmatica.exe on exit. If you install the program (and run it at least once) in the admin account and then attempt to use it from a limited user account, the security permissions on the file will not allow the limited user account to overwrite the file.

    If you want to preserve your configuration as-is without saving any future changes you may make, you can simply turn this off (running under the admin account) by unchecking the "Save Settings on Exit" box at the top of the "General" tab in the Global Settings dialog box (Options/Settings menu item). This will write out the settings file one last time, after which you can run in the limited user account and it will not attempt to write to the file anymore.

    On the other hand, if you'd like to support multiple user accounts, each with its own independent configuration, you can do so as follows:

    • Install under the admin account so the program files and start menu shortcut are available to all users.
    • Modify the shortcut to Graphmatica.exe created by the installer to include the command-line parameter "/i:%USERPROFILE%\graphmat.ini" (be sure to include the quotes in the shortcut, as the USERPROFILE directory names generally contain spaces). This will allow each user to save their own copy of graphmat.ini in their personal settings directory.

  9. Can Graphmatica solve systems of inequalities?
    No, this is not supported. If you want to find the intersection of two inequalities, just graph them both one after the other, and the common area will be shaded in both directions (/ and \). To find the intersection of 3 or more inequalities, you might try enabling the "Shade Inverse of solution for inequalities" option in the Global Settings dialog box (Options/Settings menu item). Then when you enter multiple inequalities, the area which solves all of them (assuming there is a solution) will be left unshaded and should be easy to spot.

  10. How do I view the help file on Vista?
    Unless you are using the French help file (which has not yet been reformatted), you should just upgrade to
    version 2.3, which comes with help in the new HTML Help format preferred by Windows 7 and Vista (as well as Windows 2000 and XP).

    For reasons I cannot fathom, Microsoft decided to "trim down" Vista to a lean, mean, 2+ GB by removing support for the original Windows 32-bit help format from the product. So by default, you will likely get an error upon attempting to open the help file on Vista. You can add support for this format of help (in any product) back to the OS by installing this package from Microsoft.

  11. How do I perform a silent/unattended install on Windows?
    Using the new Microsoft Installer (.msi)-based installer, this is easy as pie. Just run the command line:
    msiexec /i Graphmatica23.msi /q
    
    (Of course the .msi filename needs to match the version you actually downloaded.)

  12. I am trying to print graphs along with equations formatted using the equation editor in Word 2007 (or 2010) on Windows XP (or 2003) and the equations don't print. What's wrong?
    This is apparently a bug in the equation editor bundled with Word/Office 2007 and newer. You may be able to work around it by printing to a .pdf file and then printing the pdf from Adobe Acrobat. For best results, though, reconfigure your Windows installation by following
    these steps from the Microsoft Knowledgebase.

  13. Nothing happens (or, in newer versions, I get an error message pointing me here) when I try to paste a data plot from Excel. Why?
    "Security" software such as
    WebRoot SecureAnywhere may be blocking Graphmatica's access to the clipboard in the name of protecting your privacy. SecureAnywhere appears to be bundled with recent Lenovo computers with Windows 8 preinstalled. You can avoid issues with SecureAnywhere by adding Graphmatica to the "allowed" application list for its IdentityShield component by following the instructions that begin at page 17 of this document.

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kSoft, Inc. ksoft@graphmatica.com Last updated: Wed 05 Mar 2014