XPP has many options that allow you to save the state of the system, data generated by the program, postscript figures, etc. We have not looked at these in the tutorial in order to avoid clogging up temporary directories formed by the Web Browser with files that you won't need for the tutorials. However, for the homeworks, it is best to make hard copy so that they can be looked at by the instructors.
This section presents a howto for different types of input and output that you will want for general use of the program.
Similarly, any file that has this simple format can be read by XPP and plotted within the program. XPP will only load in as many columns as it has allocated.
Within the AUTO window , you can write the numerical values that appear on the bifurcation diagram in a three column file containing the parameter in the first column, the minimum in the second and the maximum in the third column. To do this, within the AUTO window, click (File) (Write Pts) and give a filename.
Similarly, click on (File) (Read set) to get the saved state.
XPP lets you write a "Human Readable" version of this by clicking (File) (Save info) to write to a file and (File) (Prt info) to write to the terminal.
To make a postscript file for a bifurcation diagram, within the AUTO window, click (File) (Postscript) and enter a filename.
9x15 BIG_FONT_NAME <-- menu fonts fixed SMALL_FONT_NAME <-- IC, browser, etc fonts 0 BACKGROUND (1=white,0=black) 0 IXPLT <-- X-axis variable (0=time) 1 IYPLT <-- Y-axis variable 1 IZPLT <-- Z-axis variable 3 AXES <-- type of axis 1 NJMP <-- nOutput 40 NMESH <-- Nullcline mesh 4 METHOD <-- Integration method 1 TIMEPLOT <--- set to zero if one axis is not time 8000 MAXSTOR <--- maximum rows stored 20.0 TEND <-- total integration time .05 DT <--- time step 0.0 T0 <-- start time 0.0 TRANS <-- transient 100. BOUND <--- bounds .0001 HMIN <-- min step for GEAR 1.0 HMAX <-- max `` `` `` .00001 TOLER <-- tolerance for GEAR 0.0 DELAY <-- maximal delay 0.0 XLO <--- 2D window sizes 20.0 XHI -2.0 YLO 2.0 YHI