MATLAB: How to implement “interp2” in Simulink without using a MATLAB Function block

2dimensionalinterp2interpolationlookupsimulinktable

How can I implement "interp2" in Simulink without using a MATLAB Function block?

Best Answer

A functionality that is identical to "interp2" can be implemented in Simulink using a 2-D Lookup Table.
For instance, let us assume that we would like to interpolate in the "peaks" function as evaluated over an X-Y grid where both X and Y vary from -3 to 3 with increments of 1.
In this case, the breakpoints for the lookup table should be entered as
 
[-3:3]
Notice that the breakpoints are supplied as regular 1-D arrays. The table data, however, should be the function "peaks" evaluated over a 7-by-7 grid, as shown below.
 
[X,Y] = meshgrid(-3:3);
V = peaks(X,Y);
The variable "V" can then be supplied as table data in the 2-D Lookup Table dialog box.
Now the lookup table inputs u1 and u2 will correspond to the query points Yq and Xq, respectively.
The block will return a scalar output in response to scalar inputs. 
If the inputs are 2-D grid coordinates, as constructed by the "meshgrid" function, the block will output a matrix.
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