Operands to the logical AND (&&) and OR (||) operators must be convertible to logical scalar values. Use the ANY or ALL functions to reduce operands to logical scalar values.

Question

Sal 2024-3-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2094591-operands-to-the-logical-and-and-or-operators-must-be-convertible-to-logical-scalar-values

评论： Sal 2024-3-19

function [y,Err,n] = ARCTANA(x)
[rows,columns]=size(x);
y_plot=zeros(rows,columns);
err_plot=zeros(rows,columns);
n_plot=zeros(rows,columns);
for f=1:rows
for g=1:columns
v=x(f,g);
if v<=-1
N=50;
y=(-pi/2);
    for k=0:N
    an=((-1)^k)/((2*k+1)*(v^(2*k+1)));
    y=y-an;
    end
real=atan(v);
Err=abs(real-y);
n=N;
elseif -1<v & v<1
an=v;
y=an;
k=1;
    while abs(an)>1E-12
    an=(((-1)^k)*v^(2*k+1)/(2*k+1));
    y=y+an;
    k=k+1;
    end
real=atan(v);
Err=abs(real-y);
n=k-1;
else
an=1/v;
y=(pi/2);
k=0;
    while abs(an)>1E-12 & k<=50
    an=((-1)^k)/((2*k+1)*(v^(2*k+1)));
    y=y-an;
    k=k+1;
    end
real=atan(v);
Err=abs(real-y);
n=k;
end
y_plot(f,g)=y;
y=y_plot;
n_plot(f,g)=n;
n=n_plot
err_plot(f,g)=Err;
Err=err_plot;
end
end

This is the code I wrote

******* GRADING OUTPUT *******
Function name.......CORRECT
       inputs.......CORRECT +1 points
      outputs.......CORRECT +1 points
Calling function [y, Err, n] = ARCTANA(1 x 1 array)
	Grading variable y........correct size +0.5 points
                          ....correct value +0.5 points
	Grading variable Err........correct size +0.5 points
                            ....correct value +0.5 points
	Grading variable n........correct size +0.5 points
                          ....correct value +0.5 points
Calling function [y, Err, n] = ARCTANA(3 x 5 array)
	Grading variable y........correct size +0.5 points
                          ....correct value +0.5 points
	Grading variable Err........correct size +0.5 points
                            ....correct value +0.5 points
	Grading variable n....Operands to the logical AND (&&) and OR (||) operators must be convertible to logical scalar values. Use the ANY or ALL functions to reduce operands to logical
scalar values.
Error in TestARCTANA
Error in TestARCTANA
Error in TestARCTANA
 

This is the output of the P-code and I am confused on what is wrong. If I enter a "test" array myself through the function it works just fine.

2 个评论
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Walter Roberson 2024-3-14

在 MATLAB Online 中打开

n_plot(f,g)=n;
n=n_plot

That is suspicious, that you are returning a 2 d array for n.

Catalytic 2024-3-14

在 MATLAB Online 中打开

I highly recommend against "f" and "g" as symbols for loop indices. It is terribly unreadable to others -

for f=1:rows
for g=1:columns

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Answer 1

Walter Roberson 2024-3-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2094591-operands-to-the-logical-and-and-or-operators-must-be-convertible-to-logical-scalar-values#answer_1425526

移动：Walter Roberson 2024-3-14

You would get this error if the grading system is expecting n to be a scalar but n is a 2D array instead.

6 个评论
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Sal 2024-3-18

在 MATLAB Online 中打开

I thought that also but I do not believe it is the case. If I enter this code it just doesn't give me the points

function [y,Err,n] = ARCTANA(x)
[rows,columns]=size(x);
y_plot=zeros(rows,columns);
err_plot=zeros(rows,columns);
n_plot=zeros(rows,columns);
for f=1:rows
for g=1:columns
v=x(f,g);
if v<=-1
N=50;
y=(-pi/2);
    for k=0:N
    an=((-1)^k)/((2*k+1)*(v^(2*k+1)));
    y=y-an;
    end
real=atan(v);
Err=abs(real-y);
n=N;
elseif -1<v & v<1
an=v;
y=an;
k=1;
    while abs(an)>1E-12
    an=(((-1)^k)*v^(2*k+1)/(2*k+1));
    y=y+an;
    k=k+1;
    end
real=atan(v);
Err=abs(real-y);
n=k-1;
else
an=1/v;
y=(pi/2);
k=0;
    while abs(an)>1E-12 & k<=50
    an=((-1)^k)/((2*k+1)*(v^(2*k+1)));
    y=y-an;
    k=k+1;
    end
real=atan(v);
Err=abs(real-y);
n=k;
end
y_plot(f,g)=y;
y=y_plot;
err_plot(f,g)=Err;
Err=err_plot;
n=[1 1 1;1 1 1;1 1 1];
end
end
******* GRADING OUTPUT *******
Function name.......CORRECT
       inputs.......CORRECT +1 points
      outputs.......CORRECT +1 points
Calling function [y, Err, n] = ARCTANA(1 x 1 array)
	Grading variable y........correct size +0.5 points
                          ....correct value +0.5 points
	Grading variable Err........correct size +0.5 points
                            ....correct value +0.5 points
	Grading variable n........ERROR: incorrect size
....ERROR
Calling function [y, Err, n] = ARCTANA(3 x 5 array)
	Grading variable y........correct size +0.5 points
                          ....correct value +0.5 points
	Grading variable Err........correct size +0.5 points
                            ....correct value +0.5 points
	Grading variable n........ERROR: incorrect size
....ERROR
Calling function [y, Err, n] = ARCTANA(9 x 7 array)
	Grading variable y........correct size +0.5 points
                          ....correct value +0.5 points
	Grading variable Err........correct size +0.5 points
                            ....correct value +0.5 points
	Grading variable n........ERROR: incorrect size
....ERROR
        HINT: You need to calculate the arctan value with individual elements in the x array.
              How many x array elements are there? How do you indicate each individual element?
Final grade: 8/11

Walter Roberson 2024-3-18

The grading system contains instructor-written tests for the correctness of variables. The instructor did not think of the possibility that n might not be scalar, and accidentally wrote tests that assume that it is scalar.

Sal 2024-3-19