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Topic: Graphically add or nonlinear rescale
Replies: 4   Last Post: Nov 12, 2012 9:50 AM

 Messages: [ Previous | Next ]
 Peter Mairhofer Posts: 41 Registered: 8/18/10
Re: Graphically add or nonlinear rescale
Posted: Nov 12, 2012 12:01 AM

On 11/11/2012 8:03 PM, Nasser M. Abbasi wrote:
> On 11/11/2012 8:57 PM, Peter Mairhofer wrote:
>> Hi,
>>
>> I have two non-linear functions f1 and f2, both with a non-linear
>> scaling vector x1 and x2.
>>
>> When I use
>>
>> plot(x1, f1); hold on;
>> plot(x2, f2, 'r');
>>
>> MATLAB perfectly prints the two graphs, no matter that x1 and x2 have
>> different (nonlinear) structure (in particular, x1 and x2 are
>> logarithmic and have different lengths).
>>
>> Now I want to add these functions. But I can't just add f1 and f2
>> because the lengths are different and the x-axis do not match.
>>
>> Is there a way to rescale data or export the graphs with a given amount
>> of spacing and from/to range so that I can add them?
>>
>> Thanks,
>> Peter

Hi,

Thanks, but ...

> can't you just simply resample the data with smaller number
> of points so that it now has the same number of points as the
> larger one?

... x1 and x2 have a different scale. I.e., the sampling points of f1/f2
are not equally spaced but the spacing is given by the values in x1/x2.

> There are many ways to resample the data. You can either
> fit it to a function first, then sample the function. Or do
> it by interpolation.

plot implicitely interpolates the data points. Is there a function which
does exactly the same as plot but applied for a data vector?

Peter

Date Subject Author
11/11/12 Peter Mairhofer
11/11/12 Nasser Abbasi
11/12/12 Peter Mairhofer
11/12/12 Steven Lord
11/12/12 dpb