Make num2str in engineering format

68 views (last 30 days)
Hey, I'm writing this code:
disp(['Cutoff frequency: ',num2str(wcutoff,'%e')]);
and this displays the frequency in an normal exponential format, but I want it to be in eng format. This means that instead of:
5.2e10
I want it to show:
52.0e9
Is that possible? A possible workaround could be to use "format shortEng" and than separate the display code into 2 lines, but than I need to find a way that it'll display it in one output line or something like that...

Accepted Answer

Yoav Romach
Yoav Romach on 7 Mar 2014
Edited: Yoav Romach on 7 Mar 2014
Ok, I've actually came up with a better, simpler solution:
format shortEng
disp([' Cutoff frequency: ', strtrim(evalc('disp(wcutoff)'))]);
strtrim is needed because the evalc returns numerous leading and trailing white space, but this produces exactly the output I wanted, without the helper function.
  4 Comments
Yoav Romach
Yoav Romach on 7 Mar 2014
Haa, I see, Don't care about the credit though.
My original problem with "format shortEng" was that it didn't work :) I had to push another "evalc('disp(wcutoff)')" inside, and I only thought of that today.
Thanks a lot anyway!

Sign in to comment.

More Answers (3)

Steven Lord
Steven Lord on 22 Nov 2021
If you're using release R2021a or later I would use formattedDisplayText instead of evalc.
wcutoff = 5.2e10;
t = formattedDisplayText(wcutoff, 'NumericFormat', 'shortEng')
t =
" 52.0000e+009 "

Harry Dymond
Harry Dymond on 16 Jul 2019
For the benifit of those stumbling across this old thread in search of answers: my FEX submission num2eng will do what the OP is asking for.

Jos (10584)
Jos (10584) on 7 Mar 2014
A similar effect can be obtained by manipulating the string rather than the numbers
X = 52346574 ;
s1 = sprintf('%.2e',X)
v = sscanf(s1,'%d.%de%d')
s2 = sprintf('%d%.1fe%02d',v(1), v(2)/10, v(3)-1)
disp(['Cutoff frequency: ', s2]);
Which can be made into a function handle:
Val2EngString = @(X) sprintf('%d%.1fe%02d',[1 .1 1] .* sscanf(sprintf('%.2e',X),'%d.%de%d').' - [0 0 1])
disp(Val2EngString(2340000000))
  1 Comment
Star Strider
Star Strider on 7 Mar 2014
I never considered that approach. I’ll take a look at it.

Sign in to comment.

Categories

Find more on Loops and Conditional Statements in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!