# A little help?

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Hi there,
I am having a little problem with one of the questions for an assignment I have. I have less than basic knowlage of MALAB so this assignment is to break me in so to say.
The question states that I need to create a matrix with with the input values clamped in the range +- 1.
Any help would be much appreciated! :D
Hi guys thanks for helping.
I don't think I made myself very clear or explained my puzzle very clearly. For this I apologise
I will have a second attempt now.(Please bare in mind i am not a very experianced programer):
On my question sheetI am given a return property that is defined as oneabs. This property needs to return the input values clamped in the range of +-1.
Now I think this is asking me to return everything inbeetween and clip everything higher than +1 as 1, and everything <-1 as -1.
I hope this is a little clearer.

Image Analyst on 11 Dec 2011
Aadam: Based on your latest comment to your original question I would just make my code into a function. In file test.m:
function test()
% Generate sample data.
M = 10*rand(8) - 5; % Sample matrix.
% Clip the data to the range -1 to +1
oneabs = Clip(M)
% Clip to range (-1 to +1) if outside that range.
% Leave values alone if within that range.
function oneabs = Clip(M)
oneabs = M; % Initialize.
oneabs (M < -1) = -1;
oneabs (M > 1) = 1;

Fangjun Jiang on 11 Dec 2011
Matrix=[-0.1,0.2;-0.5,0.9]
InMatrix=4*rand(5)-2;
OutMatrix=min(InMatrix,1);
OutMatrix=max(OutMatrix,-1)
Jan on 11 Dec 2011
@Fangjun: "create a matrix with with the input values clamped in the range +- 1". Yes! I like the deeper message of this answer. +1

Mohsen Davarynejad on 11 Dec 2011
Matrix = 2*rand(10,10) - 1
Image Analyst on 11 Dec 2011
You're scaling his data, which he didn't ask for.

Image Analyst on 11 Dec 2011
M = 10*rand(8) - 5; % Sample matrix.
% Now clip to range (-1 to +1)
M(M<-1) = -1;
M(M>1) = 1;
Image Analyst on 11 Dec 2011
No you didn't try it. You didn't try my code because I never mentioned oneabs. In fact I just copied and pasted my code into MATLAB, now that I'm on a computer that has it, and it ran fine and did exactly what I said and what you asked. You'd need to post your code for us to figure out what you did wrong.

Jan on 11 Dec 2011
Another approach:
M = 10*rand(8) - 5; % Sample matrix. (Thanks IA!)
M = max(min(M, 1), -1);

Mohsen Davarynejad on 11 Dec 2011
The Matrix of interest of poster is:
A = [1,2,3;4,5,6;7,8,9];
and the soloution is the following:
B = A - min(A(:));
C=2*B./max(B(:))-1;
Image Analyst on 11 Dec 2011
Mohsen, that matrix was in response to your question and as I mentioned it's not what any of us suggested because he somehow came up with some new matrix oneabs. So who knows why he cam up with that. Now if his matrix were really that (in the range 1-9) the simplest solution would simply be M = ones(1, length(M)); Of course he'd have no values less than 1 so there's be no reason to clip there like he originally required. But he said he DID need to clamp to -1 in his question and subject line. Neither Jan nor I sees anything at all where he says "scale my data" like you gave but we do see where he says "clamp my data." Though I do agree that your code does scale, which is fine if that's what he wants (despite saying something to the contrary). Aadam, please clarify: do you want scaling or clamping?