* Many unused import cleanups
Ignored some star imports, some vendored code in colorama, only looked within pyqtgraph the library, not e.g. examples
* SpinBox decimal imported with both import and from import
Many places in the library were doing radian to degree conversion
via the manual calculation. Doing timeit benchmarks on my system, I
am able to get a 4x speedup by using math.degrees or math.radians
instead
Significant performance issues have been identified with np.clip
and thus clip_array was created to speed up the operation. In addition
clip_scalar was created to clip a scalar value between two other values
this commit replaces many uses of np.clip from operating on scalars to
using clip_scalar instead
Using numpy methods that are intended for vectorized operations is
substantially slower than using the math module, so when feasible the
math module methods should be used.
