## how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

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yanxj20
Posts: 11
Joined: 14 Jan 2021, 08:11

### how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

Hi everyone,

I am trying to use simxCallScriptFunction in matlab to get the mass of a link on Franka . After I wrote my code in threaded child script(Franka) as follows:

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getMass_function = function(inInts,inFloats,inStrings,inBuffer)
if #inInts>=1 then
mass,inertiaMatrix,centerOfMass = sim.getShapeMassAndInertia(inInts[1],nil)
return {},{mass},{},''
end
end

I need to write code in matlab. According to the synopsis of function simxCallScriptFunction in helpFile:

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 array simxCallScriptFunction(string funcAtObjName, number/string scriptType, anyType funcArgs, string topic)

my code is:

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vrep.simxCallScriptFunction('getMass_function@Franka','sim.scripttype_childscript',linkHandle,[],[],[],vrep.simx_opmode_blocking);
but I get an error:

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Not enough input arguments.

Error in remApi/simxCallScriptFunction (line 2075)
variousIntsIn_ =
libpointer('int32Ptr',int32([clientID,options,numel(inInts),numel(inFloats),strCnt,numel(inBuffer),operationMode]));

Error in c20200122getMassFromVrep (line 43)
[resM, ~, retFloatsM, ~, ~] =
vrep.simxCallScriptFunction('getMass_function@Franka','sim.scripttype_childscript',[linkHandle],[],[],[],vrep.simx_opmode_blocking);
and then I try

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[resM, ~, retFloatsM, ~, ~] = vrep.simxCallScriptFunction(clientID,'getMass_function@Franka','sim.scripttype_childscript',[linkHandle],[],[],[],vrep.simx_opmode_blocking);
The error remains the same. why? thanks!

coppelia
Posts: 8446
Joined: 14 Dec 2012, 00:25

### Re: how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

Hello,

try with following:

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[resM, retIntsM, retFloatsM, retStringsM, retBufferM] = vrep.simxCallScriptFunction(clientID,'Franka',vrep.sim_scripttype_childscript,'getMass_function',[linkHandle],[],'',[],vrep.simx_opmode_blocking);
Cheers

yanxj20
Posts: 11
Joined: 14 Jan 2021, 08:11

### Re: how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

Thanks! that error is removed but there is still something wrong. the resM is false in MATLAB and in vrep i receive:
Error: [string -unknown location]:?: Call failed. (simCallScriptFunctionEx on getMass_function@Franka)

I have no idea where the problem could be this time.==
coppelia wrote:
22 Jan 2021, 11:12
Hello,

try with following:

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[resM, retIntsM, retFloatsM, retStringsM, retBufferM] = vrep.simxCallScriptFunction(clientID,'Franka',vrep.sim_scripttype_childscript,'getMass_function',[linkHandle],[],'',[],vrep.simx_opmode_blocking);
Cheers

coppelia
Posts: 8446
Joined: 14 Dec 2012, 00:25

### Re: how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

Make sure that your function has exactly the same spalling: getMass_function
Make also sure the script the function is defined in is attached to the object Franka (also check the exact spelling).
Make sure that the script the function is defined in is a child script, and that it is (still) initialized at the time it is called.

Cheers

yanxj20
Posts: 11
Joined: 14 Jan 2021, 08:11

### Re: how to use simxCallScriptFunction in matlab to get the mass of a link on Franka

Thanks! The problem is solved! I find that the functions should be defined in a non-threaded child script, rather than threaded child script.