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Re: Calculating log for each array element
From: |
LUK ShunTim |
Subject: |
Re: Calculating log for each array element |
Date: |
Fri, 20 Jun 2008 21:47:18 +0800 |
User-agent: |
Mozilla-Thunderbird 2.0.0.14 (X11/20080509) |
DimitryASuplatov wrote:
Hello,
I have array with some values initialized as
a = load <filename>
I want now to create another array b so as b[i] = log(a[i])
I do this as follows
for i = 1:length(a)
b(i) = log(a(i))
endfor
This works but it takes to long
1/ Is there any way to speed this up?
Most octave functions works on matrices.
octave:1> a=[1 2 3 4];
octave:2> log(a)
ans =
0.00000 0.69315 1.09861 1.38629
2/ How to convert my array a to list?
3/ How to append to array?
Is this what you want?
octave:3> b=[a 10]
b =
1 2 3 4 10
octave:4> c=[a b]
c =
1 2 3 4 1 2 3 4 10
I really appreciate your help!
Thank you!
SDA
The octave manual is online at
http://www.gnu.org/software/octave/doc/interpreter/
Regards,
ST
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