# solve()

### #1

Posted 19 February 2004 - 09:08 PM

have been trying to make a program and I need to isolate the result of a solve function, i get a result as {x=0.020615} to put it into a variable ant then make some operations, with this result I cant operate.

Is there any other function as eval() or similar to get only the expression? or any trick?

I've been trying to convert to a string eliminate "x=" and then use the strtoexp() but it doesn't change the type...

excuse my english, thankyou!

P.S. :What is the difference in use this and this

### #2

Posted 19 February 2004 - 10:20 PM

solve(x=1,x)=>y

In var. y is the result {x=1}

now you can operate with expr. in var. y as with list.

You can access to result by this command: y

If you have more expressions ({x=1,x=-1}), you can use y , y , ...

"(-)" and "-" is same, I think.

### #3

Posted 19 February 2004 - 10:25 PM

yes i belive they are:"(-)" and "-" is same, I think.

3' /> 2' /> = 1

3' /> 2' /> = 1

aswell, with no syn errors, so i guess they are the same

### #4

Posted 19 February 2004 - 10:47 PM

You can get left or right part of expression ("=" is center) by these commands:I've been trying to convert to a string eliminate "x=" and then use the strtoexp() but it doesn't change the type...

getLeft(EXPR)

getRight(EXPR)

so for "x=1" you'll get number 1 as: getRight(x=1)

### #5

Posted 19 February 2004 - 11:09 PM

solve(EQU,x)=>y

ExpToStr y,y //y is now a string

StrFind y,"=",smin

StrFind y,"}",smax

StrMid y,smin+1,y,smin-1 //the # part the y is stored in y

strToExp(y)=>y //y is a number

this is the programming method, in this case the mathmatical way is better.

### #6

Posted 20 February 2004 - 11:15 AM

solve(f(x),x)=>sol

'to make expr the same size as sol

sol=>expr

'The first expression

getRight(sol )=>expr

'The 2nd expression - if there is one check it with dim(sol)

getRight(sol )=>expr

'The 3rd expression- if there is one check it with dim(sol)

getRight(sol )=>expr

### #7

Posted 20 February 2004 - 03:38 PM

Ive been trying the getright() and it's what I needed.

Thankyou.Best regards

### #8

Posted 20 February 2004 - 04:28 PM

### #9

Posted 25 February 2004 - 05:46 PM

solve(x=1,x)=>y

In var. y is the result {x=1}

now you can operate with expr. in var. y as with list.

You can access to result by this command: y

By the way, this also works with ANS so you don't have to save the result to a variable, if it's to be used only once afterwards.

ANS will return the first list item. ANS the second, and so on.

__tonyp__

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