GNUplot37 is a version of GNUplot 3.7.3, a popular open-source math-graphics and plotting package. It can generate accurate visualizations of mathematical functions, as well as creating multi-colour plots of existing data series. It is a more advanced version of the GNUplot 3.2 that was the companion product to GEMESYS sAPL, an APL Language environment for the Blackberry Playbook. GNUplot37 can plot time-series data, such as stock-prices or other financial variables, such as economic indexes, interest-rates series, or money-supply values. It can also be used as a visualization tool to support learning basic and advanced mathematics. Students can enter simple plotting commands, such as "plot sin(x)", and generate an immediate visual image of the function. GNUplot is a robust, well-documented open-source product which has been around for many years, and allows complete control graphics generation and display on a wide variety of platforms. GEMESYS Software is pleased to bring this well-known workhorse to the Android platform as part of our commitment to the open-source development model. This version makes use of the DOSbox emulation environment, and has been tested to ensure numerical accuracy. Enhancements to the mathematical capabilities of DOSbox (which will be made available soon as "gDosBox") were made to ensure the operational accuracy of GNUplot37.
The GNUplot37 application comes with several demonstration plot files, which are installed on the "/sdcard" area of your Android device. These files and can be examined, copied and modified, if you wish, or you can run them all by entering load "all.dem" in response to the gnuplot> prompt. GNUplot is a traditional command-line application, which requires keyboard input. On an Android screen, you bring up the keyboard by pressing the small key "Ab" in the top left corner of the screen. When GNUplot37 first starts, just press the OK button to begin. Enter "plot sin(x)" to create a first plot. Press the bottom right screen button "1", to return to gnuplot> prompt. You may enter "!cls" to clear the screen (so you can see what you type, with the keyboard displayed.) You can "shell out" to "Dosbox" with the "!" command, and inspect the sample files provided. Type "exit" to return to "gnuplot>" prompt, and "exit" to return to Android screen.
Plots that appear on the screen, can be copied to Android clipboard by taking a screen-shot. On Android 4.1, that is a button on screen bottom, but on Android 4.2.2 (the Samsung Galaxy Tab3) and Android 5.0.2 (Galaxy Tab-A), you press power-button plus front-screen button. Or, you can set options within GNUplot to output the plot results to a .gif file, and transfer that file to another location, using any of the numerous communication methods available to Android users.
You can explore an online help file for Gnuplot37 by entering "Help" to the gnuplot> prompt. Note that on more recent versions of Android, the keyboard is made to go away by pressing the "back" button (eg. the Samsung Galaxy 4.2 and above models), whereas on Android 4.1 and earlier, a down-arrow key on the left side of the keyboard clears it from the display.
*** GNUplot37 now runs on Android-5 ! The change involved re-coding jobject pointers that were local static to use the NewGlobalRef feature, first documented in Android ICS (Ice Cream Sandwich), and now part of the new ART (Android Run Time engine) in Android 5 (Lollipop) devices. GNUplot37 users are encourged to forward operation reports to our email address. Current testing has been limited to Android 5.0.2 tablets, including Samsung Galaxy Tab-A, Tab-3 and Tab-4.
Initial version, 0.7.5. Still somewhat experimental.