Vector Calculus in Bash Scripts

When performing preparatory operations for e.g. CFD or FEM analyses, it is often necessary to specify vector parameters. Vector constants are easy to handle:

However, it quickly becomes complicated if the vectors have to be manipulated, e.g. multiplied by scalars or rotated.

A powerful solution is to use the Matlab Octave clone to perform the operations. Two features of octave are useful in this context:

  • the command line option “–eval” to specify the expression to handle
  • the function “disp” to output the results in plain format in a single line

An example:

More complicated operation are possible. Though one needs to take care to produce line vectors as results. Rotation as an example: