Incorrect argument data type or missing argument in call to function 'sqrt'.

clc

Lc0 = ureal('Lc0',4.2e-3,'percent',10);

Lg0 = ureal('Lgo',2.5e-3,'percent',30);

Cf0 = ureal('Cf0',8e-6,'percent',10);

wr=sqrt((Lc0+Lg0)/(Lc0*Lg0*Cf0));

gives following error

Check for incorrect argument data type or missing argument in call to function 'sqrt'.

Answer 1

[VBBV]

clc
Lc0 = ureal('Lc0',4.2e-3,'percent',10)   

Uncertain real parameter "Lc0" with nominal value 0.0042 and variability [-10,10]%.

Lg0 = ureal('Lgo',2.5e-3,'percent',30) 

Uncertain real parameter "Lgo" with nominal value 0.0025 and variability [-30,30]%.

Cf0 = ureal('Cf0',8e-6,'percent',10) 

Uncertain real parameter "Cf0" with nominal value 8e-06 and variability [-10,10]%.

wr=sqrt((Lc0.NominalValue+Lg0.NominalValue)./(Lc0.NominalValue*Lg0.NominalValue*Cf0.NominalValue))

wr = 8.9310e+03

[VBBV]

From the outputs of ureal function, it is evident that you need to specify a Nominal value to evaluate the expression within sqrt function. From the doc page of ureal function, the nominal value can be accessed similar to a struct variable within the range inputs

[VBBV]

clc
Lc0 = ureal('Lc0',4.2e-3,'percent',10)   

Uncertain real parameter "Lc0" with nominal value 0.0042 and variability [-10,10]%.

get(Lc0)

    NominalValue: 0.0042
            Mode: 'Percentage'
           Range: [0.0038 0.0046]
       PlusMinus: [-4.2000e-04 4.2000e-04]
      Percentage: [-10.0000 10.0000]
    AutoSimplify: 'basic'
            Name: 'Lc0'

Lg0 = ureal('Lgo',2.5e-3,'percent',30) 

Uncertain real parameter "Lgo" with nominal value 0.0025 and variability [-30,30]%.

get(Lg0)

    NominalValue: 0.0025
            Mode: 'Percentage'
           Range: [0.0018 0.0033]
       PlusMinus: [-7.5000e-04 7.5000e-04]
      Percentage: [-30 30]
    AutoSimplify: 'basic'
            Name: 'Lgo'

Cf0 = ureal('Cf0',8e-6,'percent',10) 

Uncertain real parameter "Cf0" with nominal value 8e-06 and variability [-10,10]%.

get(Cf0)

    NominalValue: 8.0000e-06
            Mode: 'Percentage'
           Range: [7.2000e-06 8.8000e-06]
       PlusMinus: [-8.0000e-07 8.0000e-07]
      Percentage: [-10 10]
    AutoSimplify: 'basic'
            Name: 'Cf0'

Answer 2

[Vishnu Vardhan]

Hi Amulya,

In this case "sqrt" function is not accepting ureal objects. So instead, try it by changing into double precession scalar.

Here is the sample code:

clc;
Lc0 = ureal('Lc0',4.2e-3,'percent',10);   
Lg0 = ureal('Lgo',2.5e-3,'percent',30); 
Cf0 = ureal('Cf0',8e-6,'percent',10); 
x = (double(Lc0) + double(Lg0)) / (double(Lc0) * double(Lg0) * double(Cf0));
wr = sqrt(x);

Also, note that this error can occur even if the input is negative.

Answer 3

[RANGA BHARATH]

Hi @Amulya. Here is the solution and code for your question.

Question: Incorrect argument data type or missing argument in call to function 'sqrt'.

Solution:

If you go inside the ureal variables you have created, there are some properties associated with the uncertian real parameters.

And there is a property called NominalValue. It has a 'numerical value' and data type associated with it is 'double'.

So, it is evident that instead of passing the whole uncertain real parameter into the sqrt function, you can pass only the NominalValue or you can also typecast the parameter into double.

Code:

clc
Lc0 = ureal('Lc0',4.2e-3,'percent',10)  

Uncertain real parameter "Lc0" with nominal value 0.0042 and variability [-10,10]%.

Lg0 = ureal('Lgo',2.5e-3,'percent',30) 

Uncertain real parameter "Lgo" with nominal value 0.0025 and variability [-30,30]%.

Cf0 = ureal('Cf0',8e-6,'percent',10)

Uncertain real parameter "Cf0" with nominal value 8e-06 and variability [-10,10]%.

%% Typecasting
sqrt((double(Lc0) + double(Lg0)) / (double(Lc0) * double(Lg0) * double(Cf0)))

ans = 8.9310e+03

%% Specifying the NominalValue
wr=sqrt((Lc0.NominalValue+Lg0.NominalValue)/(Lc0.NominalValue*Lg0.NominalValue*Cf0.NominalValue))

wr = 8.9310e+03

Links to Documentation:

• Here is the link to the documentation of ureal to know accessing a particular property of the uncertain real parameter: Uncertain real parameter - MATLAB - MathWorks India