Topic: TEXT to REAL..

[Andrea]

Sorry, I know I have posted something similar few days ago..

but I can find a way to have the precision of 8 digit after the point.
I have this...

(setq a "2.06112265" )

I need to transform to REAL...

(read a)  = 2.06112
(atof a)  = 2.06112

How can I get the precision...in REAL...

note: my LUPREC variable is set to 8

[Keith™]

The value is only displayed truncated ... the value is correct in the variable .. to test it, try this:

Code: [Select]

(setq a "2.06112265")
!a
"2.06112265"
(setq b (distof a))
2.06112
!b
2.06112
(rtos b 2 8)
"2.06112265"


[Andrea]

The value is only displayed truncated ... the value is correct in the variable .. to test it, try this:

Code: [Select]

(setq a "2.06112265")
!a
"2.06112265"
(setq b (distof a))
2.06112
!b
2.06112
(rtos b 2 8)
"2.06112265"


thanks Keith..

but ho can I divide 1 by b ??

[Keith™]

Code: [Select]

(setq c (/ 1.0 (distof b)))

[Andrea]

Code: [Select]

(setq c (/ 1.0 (distof b)))

Keith...

b is alraydy in REAL...I think you want write this..

Code: [Select]

(setq c (/ 1.0 b))
but the result is..
0.485172
and must be 0.485172486

also, if i write

Code: [Select]

(rtos c 2 8)I obtain this result..."0.48517249"

not better..

I need to do this..

(/ 1 "2.06112265")
to have the exact result....

"0.485172486"

[LE]

What are you doing [or trying to do] ?.... is that value going for an output?.... or is for an internal use?

[Jeff_M]

(/ 1 "2.06112265")
to have the exact result....
"0.485172486"

Andrea, the true value is stored in the variable. You may not 'see' it but, rest assured, the computer does. To verify this, set the precision that RTOS outputs to a higher value:

Code: [Select]

(setq c (/ 1.0 b))
0.485172

(rtos c 2 16)
"0.4851724859750583"


[Keith™]

Andrea, Indeed you are correct, I had meant to use (distof a) instead.

16 is the smallest accuracy you can obtain in rtos, unless it has changed in recent versions ...

[Andrea]

OK....so if I understand....

Code: [Select]

(setq c (/ 1.0 b))
0.485172 is in fact 0.4851724859750583
but it do not showing me all right ?

to see all digit..i need to do..(rtos c 2 16)
ti have..."0.4851724859750583"

so the final result of this will be...

Code: [Select]

(setq d (rtos (/ 1.0 b) 2 16))
even b not showing all digit..
isn't it ?

thanks.

[Keith™]

exactly

[Andrea]

finally...

thanks...