What to look out for in MATLAB programming?

F12 sets breakpointsF10 single-step debugging makes use of MATLAB vector operations as much as possible, and uses fewer cycles. Add a semicolon at the end of each line, and the calculation result is not displayed on the command line, which can speed up the operation. ......

In MATLAB keying, the following matters need to be paid attention to.

a.Use variables with the same name as a matlab function or command.

b.Do not use dusty variables with the same name as MATLAB functions or commands.

c.Create an M file with the same name as the MATLAB function.

d.Create an M file with the same name as the MATLAB command.

Correct answer: B

Knowing io=1, l=, =45°, find dx and dy. Analyzing the known relation, we see that the equation can be solved with the vpasolve function.

syms dx dy

i1=io*cos(θ)l+dx)*(l+dy);i2=io*cos(θ)l-dx)*(l+dy);

i3=io*cos(θ)l-dx)*(l-dy);i4=io*cos(θ)l+dx)*(l-dy);

dx=l*((i1+i4)-(i2+i3))/io；dy=l*((i1+i2)-(i3+i4))/io；

dx,dy]=vpasolve(dx-l*((i1+i4)-(i2+i3))/io,dy-l*((i1+i2)-(i3+i4))/io)

Result: dx=0, dy=0

The assignment is a = sign, and you seem to use == in **, you see if it's because of this reason.

This is the matrix multiplication, a is 2*2 and b is 2*2, so the result of the final multiplication is also 2*2 size.

The specific process: the first row of A is multiplied and summed by the first column of B, that is, 1*4+2*3, and this result is 10 in the last C; Then the first row of A is multiplied and summed with the second column of B, as 14 in C; The second row of re-A is multiplied and summed with the first column of B, as 31 of C; Finally, the second row of A and the second column of B are multiplied and summed, as 38 of C

Remember the rules: the sum of the first row and the first column = result (c11 of the matrix); Multiplication sum of the first and second columns = result (c12 of the matrix, elements of the second column of the first row in c); Sum of the second row and the first column multiplication = result (C21 of the matrix); The sum of the second row and the second column = result (C22 of the matrix).

Three rows, three columns, one argument.