Problem using shapefile in matlab

I'm working with the free m_map toolbox for the first time. I would like to overlay an image with a vector (shape file) "clip" by doing this:

M=m_shaperead('clip'); 
clf;
for k=1:length(M.ncst), 

line((M.ncst{k}(:,1)),M.ncst{k}(:,2)); 
end;

I got the following message:

Subscript indices must either be real positive integers or logicals.

Error in carta4 (line 5)
  line((M.ncst{k}(:,1)),M.ncst{k}(:,2));

these are simple positive lat/lon values, for example: 13.2130 17.2304, even when transforming these values to integer ( 13210 17230) the error persists, could someone explain me which is the easiest way of reading shapefiles with the m_map toolbox?

Thank you very much

Answer 1

[Kelly Kearney]

I don't see anything wrong with that code, and substituting another shapefile works fine. Can you show us the details of M?

Are you sure you copied your code correctly? The error isn't in the shapefile read, but rather in the plotting line. It seems to indicate that k isn't an integer, but I'm not sure how that could occur.

On a side note, you seem to have an extra set of parentheses in there (around M.ncst{k}(:,1)), but again I don't think that would cause any issues.

Answer 2

[Jose Luis]

Thank you for your answer,I don't have any idea why this happens, an example of the data:

M =

         version: 1000
      shape_type: 5
            MBRx: [2x1 double]
            MBRy: [2x1 double]
            MBRz: [2x1 double]
            MBRm: [2x1 double]
    filelength16: 98
            type: 5
           ctype: 'polygon'
            ncst: {12x1 cell}
             mbr: [12x4 double]
      dbfversion: 3
         dfbdate: [2014 6 10]
      fieldnames: {'REC_NUM'  'DATA_VALUE'}
         dbfdata: {12x2 cell}
         REC_NUM: {12x1 cell}
      DATA_VALUE: {12x1 cell}

M.ncst

ans =

    [ 98x2 double]
    [151x2 double]
    [222x2 double]
    [ 69x2 double]
    [426x2 double]
    [843x2 double]
    [373x2 double]
    [554x2 double]
    [406x2 double]
    [111x2 double]
    [551x2 double]
    [372x2 double]

M.ncst{1}

ans =

    3.6050   11.6969
    3.5916   11.6746
    3.5612   11.6016
    3.5397   11.5000
    2.0901   11.5000
    2.1854   11.5972
    2.2062   11.6009
    2.2574   11.6479
    2.3057   11.6744
    2.3097   11.6797
    2.3038   11.6858
    2.3066   11.6968
    2.2992   11.7208
    2.3036   11.7352
    2.3191   11.7562
    2.3382   11.7702
    2.3403   11.7853
    2.3709   11.7928
    2.3677   11.8133
    2.3831   11.8276
    2.3754   11.8333
    2.3754   11.8444
    2.3792   11.8540
    2.4026   11.8705
    2.3944   11.8892
    2.4054   11.9016
    2.4047   11.9096
    2.3901   11.9308
    2.4015   11.9529
    2.4125   11.9494
    2.4200   11.9551
    2.4312   11.9553
    2.4326   11.9751
    2.4427   11.9822
    2.4588   11.9762
    2.4684   11.9946
    2.4600   12.0321
    2.4227   12.0895
    2.3998   12.1426
    2.3873   12.2422
    2.4037   12.2493
    2.4254   12.2514
    2.4345   12.2632
    2.4560   12.2545
    2.4645   12.2722
    2.4944   12.2686
    2.5056   12.2774
    2.5080   12.2886
    2.5143   12.2944
    2.5360   12.2745
    2.5735   12.2820
    2.5878   12.2997
    2.5960   12.2972
    2.6086   12.3008
    2.6250   12.2948
    2.6631   12.3041
    2.6759   12.2965
    2.6820   12.2795
    2.6862   12.2806
    2.7158   12.3493
    2.7288   12.3626
    2.7329   12.3621
    2.7751   12.4110
    2.7946   12.4183
    2.8058   12.4174
    2.8666   12.3897
    2.9585   12.2944
    2.9814   12.2859
    3.0015   12.2723
    3.0198   12.2368
    3.0489   12.2107
    3.0568   12.1906
    3.1212   12.1534
    3.1209   12.1405
    3.1248   12.1363
    3.1524   12.1215
    3.1898   12.0797
    3.2617   12.0161
    3.2485   11.9941
    3.2688   11.9729
    3.2756   11.9407
    3.2910   11.9314
    3.3020   11.8941
    3.3076   11.8876
    3.3394   11.8852
    3.3709   11.8910
    3.3840   11.8845
    3.4120   11.8807
    3.4400   11.8604
    3.4685   11.8629
    3.4850   11.8543
    3.5143   11.8246
    3.5263   11.7834
    3.5585   11.7766
    3.5594   11.7651
    3.5484   11.7437
    3.5551   11.7304
    3.6050   11.6969

[Kelly Kearney]

Okay, that all looks fine. What is the value of k when the code throws the error?