avwhite / phplotter Goto Github PK

The test userinterface is shit at the moment, make it better. ;)

cfunc assumes correctly formatted expressions(except for unkown characters, it ignores those). There should be error handling.

Results in a division by zero error. Since it is a part of the graph drawing, it might be a little tricky, since graph drawing is also whats shows the error.

At least it seems that way. Haven't had the time to investigate further.

The plotter should draw connected lines instead of spots.

This gets more complicated when you consider undefined areas in the function. This should probably first be implemented after cfunc gets support for undefined values.

Right now that axis are just lines.

The trigonometric functions are the most important.

Even when accounting for the fact that division by 0 isen't handled properly, by doing 1/(x+1).

It just gives a straight line at y=0.

You should be able to choose x-min, x-max and y-min y-max values, that decide what part of the graph is drawn.

The scaling functionality will still be needed, but the amount of scaling will be calculated by the difference between the x/y-min/max values, instead of set by the user.

The tokenizer function in cfunc.php does not handle decimal numbers.

I think it has something to do with the tokenizer not properly recusively handling the brackets.

Right now, when evaluation a function. Things like division by 0 can happen. It is quite important to handle this, as drawing graphs is all about throwing a bunch of numbers after a function, and none of them must make it crash.

So the evalu method should ba able to return some kind of 'not defined' value.

Also, the draw function should be able to handle this.

Draws through x coordinates for which f(x) is undefined, if the function dosen't excatly hit the undefined value.

This is a hard problem, and i might not be able to solve it before hand in.

plot.php should be able to draw a very simple graph, scaling atleast on the x-axis.

drawing one point per pixel in the x axis is okay, no line between them is required for this issue.

Right now there is only scaling on the x-axis, the y-axis always goes from 0 to 500.