You can assign a value to a variable with the := operator. For example, to give the variable a the value of 4, enter:
| a:=4 |
Alternatively, use the => operator; when you use this operator, the value comes before the variable:
| 4=>a |
The function sto (or Store) can also be used; again, the value comes before the variable (the value is stored into the variable):
| sto(4,a) |
After any one of these commands, whenever you use the variable a in an expression, it will be replaced by 4.
use sequences or lists to make multiple assignments at the same time. For example,
| (a,b,c):=(1,2,3) |
will assign a the value 1, b the value 2 and c the value 3. Note that this can be used to swap the values of two variables; with a and b as above, the command
| (a,b):=(b,a) |
will set a equal to b’s original value, namely 2, and will set b equal to a’s original value, namely 1.
Another way to assign values to variables, useful in Maple mode, is with the assign command. If you enter
| assign(a,3) |
| assign(a=3) |
then a will have the value 3. You can assign multiple values at once; if you enter
| assign([a=1,b=2]) |
then a will have the value 1 and b will have the value 2. This command can be useful in Maple mode, where solutions of equations are returned as equations. For example, if you enter (in Maple mode):
| sol:=solve([x+y=1,y=2],[x,y]) |
(see Section 9.3.6), you will get
|
If you then enter
| assign(sol) |
the variable x will have value -1 and y will have the value 2. This same effect can be achieved in standard Xcas mode, where
| sol:=solve([x+y=1,y=2],[x,y]) |
will return
|
In this case, the command
| [x,y]:=sol[0] |
will assign x the value -1 and y the value 2.