I am working on a lab for linear algebra in MATLAB. We are told to plot a matrix using three rotation matrices in 3D.


The rotation matrices are identical to those in the posted image except for Ry, where the negative sign on the sin(theta) is actually on the other sin(theta) in the first row third column.

If I use the matrix given in my lab [-sin(theta) 1rd row, 3st column] nothing is plotted in MATLAB, however, if I use Ry given as in the picture a nice vector is plotted. So all that I am changing between these two Ry's is the negative sign, which should just mean the plotted vector has an opposite direction. However, for some reason that is not the case.

I find it weird that the three matrices I was given are identical to those in the image with the exception of the different placement of the negative sign. On Wolfram's site (Rotation Matrix -- from Wolfram MathWorld) it seems that they use this placement but the other signs are also reversed.

My professor tells me I am making a mistake somewhere in my code but it just seems strange to me that everywhere I am looking online has these rotation matrices listed differently. Thank you for any help!