real values with drawfilloval()

[piemaster]

We recently started [and some of us have finished] a Turing unit in class. we have an "alternate assignment" that was not actually assigned, but provided for extra fun.

it goes as following. Create a graphing calc screen that will output a graph based upon the above function. Plot the above function when give then domain {-3.2<x<=3.2}
the function mentioned is this. ((4 * (x ** 3)) + (3 * (x ** 2)) - (2 * x) + 6) / (x + 9)

the following is the code i have so far.

code:

var x : real := 0 function fx (x : real) : real     result ((4 * (x ** 3)) + (3 * (x ** 2)) - (2 * x) + 6) / (x + 9) end fx drawfillbox(0,0,maxx,maxy,black) Draw.ThickLine(320,maxy,320,0,2,white) Draw.ThickLine(0,200,maxx,200,2,white) loop x:=-3.2 drawfilloval(x,fx(x),2,2,white) x:=x+0.1 exit when x = 3.2 end loop

as you can see, i have a function that calculates the y value for the center of the circle [which is a plot point on the graph, the x value is initially -3.2 and increases incrementally till 3.2]
the error Turing throws at me is Argument is the wrong type. I assume this means I cant use a decimal value for either coordinate in the drawfilloval. is there any way around this?


ps: I'm new here, if this post is completely out of bounds please lmk. Its not for homework, just for fun and i have valid , self-written code.
pps: I'm also new to turing, so if im going about this in a completely idiotic manner, please don't judge

[Clayton]

you simply have to take the real value that you are getting and round() it to an integer. This makes sense because you can't have 1/2 a pixel right?

[piemaster]

but if i do that, wont the graph be inaccurate? i understand you can have half a pixel, but then is the problem given flawed?

thanks for the help btw

//edit:

if i edit the code to look something like this:

code:

loop x:=-3.2 drawfilloval(round(x),round(fx(x)),2,2,white) x:=x+.1 exit when x = 3.2 end loop

the output kaboomerates itself.