Re: what to do, for the mathematically-disabled people (only half-joking)

[Brian Drummond <brian@shapes.demon.co.uk>]

On Thu, 07 Jan 2021 13:46:06 -0800, Mehdi Saada wrote:

> What would you advise, for a mathematically impaired person such as
> myself, who gets a headache trying to implement a simple vector fusion
> algorithm ?
> And however I try, a few days, changes nothing to the outcome, shit
> doesn't get done, and I'm left furious at myself. And I know it well, at
> my age, when I, am the problem.
> Are those algorithm books useful, can they really hammer the logic
> muscles in my brain ?
> Basically, I cannot see in my head the (simple, I stress that out)
> program playing out.
> 
> Thanks,
> Mehdi

Sometimes, I find mocking it up in a spreadsheet helps!

Sounds dumb, but...

Say, I can think of a testcase and I know what the output should look 
like, start with a column of figures and more columns of (transformed by 
equation) figures, and ideally a column computing an error function.

Why is the error column 0 here, but not there? ... aaah...

For example I've designed pipelined versions of algorithms that way, 
before implementing in FPGA, and LUT-based quadratic interpolators to 
approximate reciprocal and square root, to get within 1 LSB error at 
single precision (multiplication/addition are cheap in FPGA, division/
sqrt not so much)

Also mocked up James Watt's link motion, a 5th order approximation to 
straight line using only rotary motion.

YMMV.

-- Brian