> 6.4 – Avoid mathematical notations in your variable names Let’s say that some quantity in the algorithm is a matrix denoted A. Later, the algorithm requires the gradient of the matrix over the two dimensions, denoted dA = (dA/dx, dA/dy). Then the name of the the variables should not be “dA_dx” and “dA_dy”, but “gradient_x” and “gradient_y”. Similarly, if an equation system requires a convergence test, then the variables should not be “prev_dA_dx” and “dA_dx”, but “error_previous” and “error_current”. Always name things for what physical quantity they represent, not whatever letter notation the authors of the paper used (e.g. “gradient_x” and not “dA_dx”), and always express the more specific to the less specific from left to right (e.g. “gradient_x” and not “x_gradient”).
Especially when you're just starting out, creating your own naming scheme just creates more opportunities to do something wrong.