# Grapher: How to revise definitions

Discussion in 'Mac Apps and Mac App Store' started by ritachengl, Jun 7, 2013.

1. ### ritachengl macrumors newbie

Joined:
Mar 10, 2011
#1
Hi there,

I have no problems in writing definitions and equations in grapher. But when I tried to revise definitions, error message shows saying "Cannot remove definition. The definition is used by another element." But I did not remove, just replace a constant number with a new parameter. For example,

The original one:
y=x+b
b:=1

Now I want it to be:
y=x+b
b:=a
a:=2

But when I try to revise the definition of b, grapher does not allow me showing the above error message.

Anyone has the same problem and can help me with that?

Thanks a lot!!

Rita

2. ### YB24 macrumors member

Joined:
Apr 3, 2007
Location:
Dordogne-France http://y.barois.free.fr/grapher/
#2
Grapher :

Bonjour Rita,
First way. A question of sequence :
b = 1
y = x + b then
a = 2 then
modify equation b = 1 above by changing 1 into a

Second way. Render inoperative all equations using the parameter to be modified, by adding the sign = in front of them :
b = 1
y = x + b > =y = x + b
change b = 1 into b = a
a = 2
cancel = to restore y = x + b
It's very easy, done quickly, can be used for a lot of equations.

Useful free documentation for Grapher.app only (French and English) on <http://y.barois.free.fr/grapher/>

Enjoy,
YB24