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program Grapher;
{$i srl-6/srl.simba}

type YEquals = record
  TextForm: String;
  XModifier: Double;
  YModifier: Double;
end;

function solveForX(x: Integer; Equation: YEquals): Double;
begin
  result := (x * Equation.XModifier) + Equation.YModifier;
end;

function makeTPA(SolveFor: YEquals; XRange, YRange: TIntegerArray): TPointArray;
var
  x, y, i: Integer;
  tpa: TPointArray;
begin
  i := 0;
  x := XRange[0];
  for x to XRange[1] do
    begin
      tpa[i] := point(x, round(solveForX(x, SolveFor)));
      i := i + 1;
    end;
end;

procedure graph(Points: TPointArray);
var
  i = 0;
begin
  WriteLn('Graphing.');
  for i to high(Points) do
    mouse(Points[i], MOUSE_LEFT);
end;

begin
  makeTPA(['3x-2', 3, -2], [0, 10], [0, 10]);
end.   

I just included the latter part because I was in a hurry. I keep getting access violation at line 24 column 22. I have tried almost everything but haven't got it to work. I am trying to create something that draws the equation of a line in paint.

Compiled successfully in 858 ms.
Exception in Script: Runtime error: "Access violation" at line 24, column 22

I might be wrong but I made a couple mods to your "makeTPA()" function, try this out:

function makeTPA(SolveFor: YEquals; XRange, YRange: TIntegerArray): TPointArray;
var
  ex : extended;
  x, y, i: Integer;
  tpa: TPointArray;
begin
  i := 0;
  x := XRange[0];
  for x to XRange[1] do
  begin
    ex := solveForX(x, SolveFor);
    setArrayLength(result, Length(result)+1);
    result[High(result)] := point(x, round(ex));;
    i := i + 1;
  end;
end; 

From: Flight
I might be wrong but I made a couple mods to your "makeTPA()" function, try this out:

function makeTPA(SolveFor: YEquals; XRange, YRange: TIntegerArray): TPointArray;
var
  ex : extended;
  x, y, i: Integer;
  tpa: TPointArray;
begin
  i := 0;
  x := XRange[0];
  for x to XRange[1] do
  begin
    ex := solveForX(x, SolveFor);
    setArrayLength(result, Length(result)+1);
    result[High(result)] := point(x, round(ex));;
    i := i + 1;
  end;
end; 

Thanks, but why exactly was I getting an access violation on that line?

From: HardcorBoter
Thanks, but why exactly was I getting an access violation on that line?

You were accessing tpa[0] (which is only possible if the length is at least one) but the length of tpa is 0.
Remember, for general arrays the index starts with 0 ;)

From: HardcorBoter
Thanks, but why exactly was I getting an access violation on that line?

you didn't set length of your tpas.

From: bg5
you didn't set length of your tpas.

Oh, didn't know I had to do that, thanks.

From: bg5
you didn't set length of your tpas.

I didn't know for sure this would be the cause of that particular error. I found Access Violation errors usually result from grouping too many functions into a single line, for example:

sortTPAFrom(Point(Box.X1-(Player(getMyPlayer).getBasePnt), y)));

Where as you might need to store the results from these functions in variables first, then plug the variables into the procedure;

x := Box.X1-(Player(getMyPlayer).getBasePnt);
sortTPAFrom(Point(x, y));

I've had trouble with that in the past. Usually not setting the length of an array will give you an Out of Range error (when your loop hits a non-existent index in that array), rather than Access Violation.

From: Flight
I didn't know for sure this would be the cause of that particular error. I found Access Violation errors usually result from grouping too many functions into a single line, for example:

sortTPAFrom(Point(Box.X1-(Player(getMyPlayer).getBasePnt), y)));

Where as you might need to store the results from these functions in variables first, then plug the variables into the procedure;

x := Box.X1-(Player(getMyPlayer).getBasePnt);
sortTPAFrom(Point(x, y));

I've had trouble with that in the past. Usually not setting the length of an array will give you an Out of Range error (when your loop hits a non-existent index in that array), rather than Access Violation.

Lape will access violate, pascalscript will out of range. I think this is because pascalscript checks the length, and lape doesn't.

From: Flight
Usually not setting the length of an array will give you an Out of Range error (when your loop hits a non-existent index in that array), rather than Access Violation.

I get mostly access errors when borking array lengths.

program new;
var ia: array of integer;

begin
  ia[1] := 20;
end.

Compiled successfully in 296 ms.
Exception in Script: Runtime error: "Access violation" at line 5, column 9

From: Olly
Lape will access violate, pascalscript will out of range. I think this is because pascalscript checks the length, and lape doesn't.

That makes sense on past errors. Thanks for the info.