Error using matlab.io.​datastore.​Transforme​dDatastore​/read Invalid transform function defined on datastore.

While running this code:

augData = read(cds);
augptCld = augData{1,1};
augLabels = augData{1,2};
augClass = augData{1,3};

labelsother = augLabels(augClass=='other',:);
labelsPedestrian = augLabels(augClass=='Pedestrian',:);

helperDisplay3DBoxesOverlaidPointCloud(augptCld.Location,labelsother,'green',...
    labelsPedestrian,'magenta','Before Data Augmentation');

reset(cds);

classNames = {'other','Pedestrian'};
sampleLocation = fullfile("C:\Users\asus\Desktop\main",'GTsamples');
[ldsSampled,bdsSampled] = sampleLidarData(cds,classNames,'MinPoints',20,...                  
                            'Verbose',false,'WriteLocation',sampleLocation);
cdsSampled = combine(ldsSampled,bdsSampled);

numObjects = [10 10];
cdsAugmented = transform(cds,@(x)pcBboxOversample(x,cdsSampled,classNames,numObjects));

cdsAugmented = transform(cdsAugmented,@(x)augmentData(x));

augData = read(cdsAugmented);
augptCld = augData{1,1};
augLabels = augData{1,2};
augClass = augData{1,3};

labelsother = augLabels(augClass=='other',:);
labelsPedestrian = augLabels(augClass=='Pedestrian',:);

helperDisplay3DBoxesOverlaidPointCloud(augptCld.Location,labelsother,'green',...
    labelsPedestrian,'magenta','After Data Augmentation');

i got this error: Error using matlab.io.datastore.TransformedDatastore/read

Invalid transform function defined on datastore.

Caused by:

Error using pointCloud/validateAndParseInputs

Invalid argument at position 1. Expected input to be one of these types:

single, double

Instead its type was uint8.

how to convert it into single or double.

Answer 1

[Avadhoot]

Hi Gaurav,

I get that you are encountering an error while using the transformed Datastore. The error is caused because the first argument of the pointCloud function is uint8. You need to convert this to either a single or a double datatype. You can use the following syntax to convert the variable to your desired datatype.

my_variable = single(my_variable); % for converting to single
my_variable = double(my_variable); % for converting to double

You can do this before passing the variable to the "pointCloud" function to get rid of the error. This method works on arrays as well.

I hope it helps.