How to use a variable in the piecewise command

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How to use a variable in the piecewise command

ProfLisa 06 Jan 2020 20:20

I am writing a program that would allow the user to input two functions and two intervals and then graph the piecewise defined function.

:"piecewise(Y1, X≤0, Y2,X>0)”→Y3
:DispGraph

works fine but I would like to replace the "X≤0" and "X>0" with string inputs. However this results in a data type error. Any suggestions?

Re: How to use a variable in the piecewise command

Trenly 06 Jan 2020 21:03

—Thread Moved

The piecewise( command page shows how to do this in its first section of code

Re: How to use a variable in the piecewise command

ProfLisa 07 Jan 2020 17:25

The first piece of code is
piecewise(Y1,X≥0,Y2,X<0→Y3

This shows the conditions as being hard-coded values, not variables. I would like to do this:
piecewise(Y1,Str1,Y2,Str2)

I'm not sure you read my post completely.

Last edited on 07 Jan 2020 17:26 by ProfLisa Show more

Re: How to use a variable in the piecewise command

Trenly 07 Jan 2020 20:02

You could try string concatenation

“piecewise(Y1,”+Str1+”,Y2,”+Str2→Y3

Re: How to use a variable in the piecewise command

ProfLisa 09 Jan 2020 00:43

Yes, this worked, thank you!

Re: How to use a variable in the piecewise command

QubicQuantum 12 Jan 2020 02:47

wouldn't you need a Str>Expr command?

Re: How to use a variable in the piecewise command

Trenly 12 Jan 2020 06:02

Not for the piecewise( command. The CE and CSE are a little different than the 83/34/+/SE

Re: How to use a variable in the piecewise command

Myles_Zadok 08 Jan 2020 04:39

I would try Trenly's suggestion, but I don't think that will work (please let me know if it does in fact work), because conditionals are a mixture of variables and conditional operators. The calculator does not seem to read the expressions the way it reads a string. The only work around I can think of would be to use a menu(s) to give the user the ability to select the desired conditional parameters.

Re: How to use a variable in the piecewise command

Trenly 08 Jan 2020 04:55

I'm doubtful it will work either, but looking at the example code on the command page, it looks like it is just storing a string into Y3, which is why I thought that concatenation may do the trick