The equations for a rotational transformation by angle A (in anticlockwise

direction) are

x' = xCos(A) - ySin(A) and y' = ySin(A) + xCos(A)

You want to plot on a diagonal (A = 45º) I know SIN(45) = COS(45) but let's

keep thing general

In F1:H1 enter this:

Angle SinA CosA

in F2 enter 45

in G2 enter =SIN(RADIANS(F2)) and in H2 =COS(RADIANS(F2))

Select F1:H2; use Insert|Name to name the cells

Now we will plot a square on the x-axis,

In A1:B1 enter x and y as headers

The x values are 2, 4, 4, 2, 2

The y values are 0, 0, 2, 2, 0

Make an XY plot - you get a 'box' on the x-axis

In C1 and D1 use headers x' and y'

In C2 enter =A2*cosA-B2*sinA; in D2 enter =B2*sinA+A2*cosA

Copy these down to row 6

Select C2

6; use Copy tool; click chart; use Edit|Paste Special

and indicate New Series with x-values in first column

Now you have the same box rotated. The box lies on the x=y line (what you

called the diagonal)

Any use?

All this is a bit esoteric so if you want to leave the newsgroup and send me

private mail that's OK with me