Amit_chaudhary asked . 2023-02-07

Why do I receive errors using IFANBEAM for matrices with NaN

Why do I receive errors using IFANBEAM for matrices with NaN values in Image Processing Toolbox 7.2 (R2011a)?

I am trying to use the function IFANBEAM on a matrix with NaN values and receive a warning and an error depending on how many NaNs the matrix contains. An example of the code, warning and error message follow:

A = rand(10, 10);

b = 100;

good_result = ifanbeam(A, b);

A(10, 1:9) = NaN;

some_result = ifanbeam(A, b);

A(10, 10) = NaN;

bad_result = ifanbeam(A, b);

 Warning: NaN found in Y, interpolation at undefined values

will result in undefined values. 

 > In interp1 at 177

   In fan2para>fan2paraInterp at 231

   In fan2para>fan2paraInterp at 221

   In fan2para at 196

   In ifanbeam at 191

   In my_program at 8 

 Warning: All data points with NaN in their value will be ignored. 

 > In polyfun\private\chckxy at 101

   In spline at 54

   In interp1 at 274

   In fan2para>fan2paraInterp at 231

   In fan2para>fan2paraInterp at 221

   In fan2para at 196

   In ifanbeam at 191

   In my_program at 8 

 Error using chckxy (line 104)

 There should be at least two data points.

 Error in spline (line 54)

 [x,y,sizey,endslopes] = chckxy(x,y);

 Error in interp1 (line 274)

         yiMat = spline(xCol.',yMat.',xiCol.').';

 Error in fan2para>fan2paraInterp (line 231)

         Fsh(i,:) = interp1(thetaDeg-gammaDeg(i),F(i,:),pthetaDeg,interp);

 Error in fan2para>fan2paraInterp (line 221)

     P = fan2paraInterp(Fpad,d,gammaDeg,thetapad,...

 Error in fan2para (line 196)

 P = fan2paraInterp(F,d,...

 Error in ifanbeam (line 191)

 [P,oploc,optheta] = fan2para(F,d,...

 Error in my_program (line 8)

 bad_result = ifanbeam(A, b);

fanbeam , Image Processing Toolbox , Image Processing and Computer Vision , Image Segmentation and A