I want to define my custom state space in matlab for my robot,i followed this tutorial ,https://i​n.mathwork​s.com/help​/nav/ref/n​av.statesp​ace-class.​html

In this as soon as i include this line

matlabshared.planning.internal.EnforceScalarHandle

it starts throwing error like illegal use of classdef ,kindly tell whats the solution to this problem

Answer 1

[Cameron Stabile]

Hi Mukund,

Without any reproduction code it is hard to determine the problem. If you have not done so already, my suggestion would be to call createPlanningTemplate from your command line:

>> createPlanningTemplate()

This should create a new file which contains the definition to a generic state-space class named "MyCustomStateSpace". Save this file under the same name (i.e. MyCustomStateSpace.m) and you should be able to create an instance of the newly defined state-space:

ss = MyCustomStateSpace

If this works, then you should be able to edit the newly saved state-space to suit your needs, and note that you can also generate a default state-validator using the same template:

createPlanningTemplate('StateValidator')

Please let us know if this resolves the issue.

Best,

Cameron

[mukund shah]

Actually i did this

classdef MyCustomStateSpace < nav.StateSpace

%matlabshared.planning.internal.EnforceScalarHandle

properties

UniformDistribution

NormalDistribution

% Specify additional properties here

end

methods

function obj = MyCustomStateSpace

spaceName = "MyCustomStateSpace";

numStateVariables = 3;

stateBounds = [0 256; % [min max]

0 256;

0 256];

[e-mail](spaceName, numStateVariables, stateBounds);

obj.NormalDistribution = matlabshared.tracking.internal.NormalDistribution(numStateVariables);

obj.UniformDistribution = matlabshared.tracking.internal.UniformDistribution(numStateVariables);

% User-defined property values here

end

function copyObj = copy(obj)

copyObj = feval(class(obj));

copyObj.StateBounds = obj.StateBounds;

copyObj.UniformDistribution = obj.UniformDistribution.copy;

copyObj.NormalDistribution = obj.NormalDistribution.copy;

end

function boundedState = enforceStateBounds(obj, state)

nav.internal.validation.validateStateMatrix(state, nan, obj.NumStateVariables, "enforceStateBounds", "state");

boundedState = state;

boundedState = min(max(boundedState, obj.StateBounds(:,1)'), ...

obj.StateBounds(:,2)');

end

function state = sampleUniform(obj, varargin)

narginchk(1,4);

[numSamples, stateBounds] = obj.validateSampleUniformInput(varargin{:});

obj.UniformDistribution.RandomVariableLimits = stateBounds;

state = obj.UniformDistribution.sample(numSamples);

end

function state = sampleGaussian(obj, meanState, stdDev, varargin)

narginchk(3,4);

[meanState, stdDev, numSamples] = obj.validateSampleGaussianInput(meanState, stdDev, varargin{:});

obj.NormalDistribution.Mean = meanState;

obj.NormalDistribution.Covariance = diag(stdDev.^2);

state = obj.NormalDistribution.sample(numSamples);

state = obj.enforceStateBounds(state);

end

function interpState = interpolate(obj, state1, state2, fraction)

narginchk(4,4);

[state1, state2, fraction] = obj.validateInterpolateInput(state1, state2, fraction);

stateDiff = state2 - state1;

interpState = state1 + fraction' * stateDiff;

end

function dist = distance(obj, state1, state2)

narginchk(3,3);

nav.internal.validation.validateStateMatrix(state1, nan, obj.NumStateVariables, "distance", "state1");

nav.internal.validation.validateStateMatrix(state2, size(state1,1), obj.NumStateVariables, "distance", "state2");

stateDiff = bsxfun(@minus, state2, state1);

dist = sqrt( sum( stateDiff.^2, 2 ) );

end

end

end

[Cameron Stabile]

Hi Mukund,

It's unclear whether your last post was a self-answer to your original question, or additional information. Did commenting out the line resolve the problem for you?

One thing to note - if your original file looked like the following:

classdef MyCustomStateSpace < nav.StateSpace 
    matlabshared.planning.internal.EnforceScalarHandle
    
    properties
        UniformDistribution
...   

Then you would likely have needed "& ..." at the end of the first line to continue inheriting from additional classes:

classdef MyCustomStateSpace < nav.StateSpace & ...
    matlabshared.planning.internal.EnforceScalarHandle
    
    properties
        UniformDistribution
...

If the issue has been resolved, please mark this question as "Answered", otherwise let us know if you are encountering further problems.

Best,

Cameron