TI-Nspire Bode Plot

[MDC]

I have been looking for a good way to do bode plots on the Nspire (I
have the CAS version although I don't think it should matter much).
The simple way would be to just plot the magnitude and the angle of
the transfer function on a graph screen. However, sometimes this
process takes too long or the calculator cannot always find these
quantities easily. I was looking for a program such as BodeX (for
TI-89/92) on http://web92.interfree.it/programs/bodex.htm which
displays bode plots quite accurately and even on a semi-log axis (in
dB). I know the programing structure of the 89 is similar to the
Nspire and I attempted to translate the program, but i ran into some
problems when the program began to use dialog boxes to prompt for
input and used the graph screen for display and interactive purposes.
So, is there any program that I have overlooked that will allow me to
do Bode plots on an Nspire? Or perhaps someone can successfully
translate the program for the Nspire.

[elkar]

The dialog boxes of the ti89 titanium and ti Voyage200 PLT are easily
programmed, but texas instrumens took the bad decision to eliminate
the operating system of the TI-Nspire CAS =(

[Nelson Sousa]

there are workarounds, though.
Although the kind of functionality you will have for the graphical
output is limited.

Input:
- use request / requestStr; limitation: only 1 var at a time; whenever
possible pass parameters on the command line;
- output: use scatter plots and a geometric construction over them, if
at all possible. you may need to limit heavily the maximum number of
allowed objects to display at the same time.

Although programming on the Nspire is much tougher than on the TI-89
with regard to input/output commands, teh workarounds still allow us
to overcome some of the difficulties (e.g., Nspir3D uses no
input/output commands at all from programs and yet displays 3D
geometry and has a handful of instructions to build objects).

Nelson

> --
> To post to this group, send email to tins...@googlegroups.com
> To unsubscribe send email to tinspire+u...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com.au/group/tinspire?hl=en-GB?hl=en-GB
> The tns documents shared by group members are archived at
> http://lafacroft.com/archive/nspire.php

[Eric Findlay]

They didn't eliminate them because they were never in the Nspire to begin with. As was stated before, dialog boxes don't fit I to the pedagogical model of the Nspire.

I've never seen this 89 program before. What did the dialog boxes do? 99% of dialog boxes and input requests can be replicated by passing in arguments to the function/program, since all the data required is known at the time the user runs the program.

For a simple example, all quadratic programs o. The 83/84 asked for A and the user inputed it, then asked for B and the user typed it in, then the same for C. Then the program went away, did the work and displayed the result.

On the Nspire, since none of the numbers required depend on the results of a mid-program calculation, the quadratic program can easily be called by typing in quadratic(A,B,C) (but swapping in values for the variables).

The only time this won't work is if some input is dependent upon the result of a calculation in the program in the form of a choice by the user. For instance, a number guessing game where the calc tells you higher or lower than your previous guess.

If your program does not fall into this category, I'm pretty sure it can be reworked to accept all needed data at the start, especially now that we have custom variable names and localization of variables.

--Eric