MaplePrimes - answers and comments on Question, How to set precision of output of writedata?

One way

Markiyan Hirnyk — Wed, 06 Mar 2013 22:58:55 Z

For example, it can be done in such a way.

> A := convert(array([[1.5123456789876543212345678, 2.2, 3.4], [2.7, 3.4, 5.6], [1.8, 3.1, 6.7]]), Matrix);

> ExportMatrix(txt, A, target = delimited, format = rectangular, mode = ascii);

See the result in C://Program Files/Maple 16/txt and ?ExportMatrix for more info.

?writedata - another option

gkokovidis — Thu, 07 Mar 2013 23:44:46 Z

Here is another way, using the float option to ?writedata. For this specific example, the output, on a WinXP machine, with be in the C:\temp drive. If you edit the file "mpltest.dat", you will see 20 digits of precision.

>	restart:Digits:=20:

>	f:=x->0.3333334444433332211*x^2;

>	Data:=[seq([i,f(i)],i=1..10)];

You have to edit the file address to a diskette or directory where you have write privileges to execute this yourself:

>	writedata("c:/temp/mpltest.dat",Data);

To see the output, you can write it to your screen:

>	writedata(terminal,Data,float);

1        0.3333334444433332211
2        1.3333337777733328844
3        3.0000009999899989899
4        5.3333351110933315376
5        8.3333361110833305275
6        12.00000399995999596
7        16.333338777723327834
8        21.33334044437332615
9        27.000008999909990909
10        33.33334444433332211

Download writedata.mw

Regards,

Georgios Kokovidis

Dräger Medical

Thanks this does work. I do however have

Lordi — Wed, 06 Mar 2013 23:22:11 Z

Thanks this does work. I do however have the data as a list - can I do a similar thing with a list or do I need to convert that list into a matrix (which I would actually be at quite a loss to do considering that the lists have a length of something like 40k entries).

Thanks for helping me :)

It is

Markiyan Hirnyk — Wed, 06 Mar 2013 23:26:57 Z

@Lordi possible. For example,

> convert([1, 2, 17], Matrix);
[1 2 17]

Also take a look at ?ExportVector .

All right

Lordi — Wed, 06 Mar 2013 23:47:24 Z

@Markiyan Hirnyk that should totally do the job :) Thanks a lot for your help, I really appreciate it :)

Digits does the job, not float

Markiyan Hirnyk — Fri, 08 Mar 2013 00:37:59 Z

Compare with

Download digits.mw