Expressions for field input

Field input validation

When adding an expression into a field, the following colors may appear, providing feedback on the validity of the expression:

Red—this denotes an error (examples include unrecognized units, unexpected character, unexpected token, unknown keyword, incomplete argument)
Green—the variable has been recognized
Orange—valid input awaiting Return key

Use when resizing a document or transforming an object via the Transform panel.

Use when resizing a document or transforming an object via the Transform panel.

Input	Result
w+20	Scales based on addition of other input value. Example entered into Height box to set height as width plus 20 pixels.
w-20	Scales based on subtraction of other input value. Example entered into Height box to set height as width minus 20 pixels.
2*w	Scaling based on a multiple of other input value. Example is entered into Height box to set height to double the width.
w/2	Scaling based on a division of other input value. Example entered into Height box to set height to half the width.
w^3	Scales based on a power of other input value. Example entered into Height box to set height as the width to the power of three.
12pt / x	Sets the text's x-height to 12pt.

For general use throughout the user interface.

Use when moving, scaling, rotating or shearing objects via the Transform panel.

Use when setting dimensions using the New Document or Document Setup dialogs.

Use when setting the size of text.

Use when sizing and positioning content using the Transform panel in relation to the document (i.e. page spread).

spreadwidth, sprw, sw	The width of the current spread
spreadheight, sprh, sh	The height of the current spread
spreadleft, sprl, sl	The position of the left edge of the current spread
spreadright, sprr, sr	The position of the right edge of the current spread
spreadtop, sprt, st	The position of the top edge of the current spread
spreadbottom, sprb, sb	The position of the bottom edge of the current spread
marginsizeleft, mgnszl, msl	The size of the left margin on the current spread
marginsizeright, mgnszr, msr	The size of the right margin on the current spread
marginsizetop, mgnszt, mst	The size of the top margin on the current spread
marginsizebottom, mgnszb, msb	The size of the bottom margin on the current spread
marginleft, mgnl, ml	The position of the left margin on the current spread
marginright, mgnr, mr	The position of the right margin on the current spread
margintop, mgnt, mt	The position of the top margin on the current spread
marginbottom, mgnb, mb	The position of the bottom margin on the current spread
designareawidth, areawidth, aw	The space between the left and right margins on the current spread
designareaheight, areaheight, ah	The space between the top and bottom margins on the current spread

For general use throughout the user interface.

Function/Usage	Notes
abs(x)	Absolute value
idiv(x,y)	Results in the integer (whole number) of x divided by y (no rounding is applied)
irem(x,y)	Results in the remainder of x divided by y
sin(a)	Sine
asin(a)	Inverse Sine
cos(a)	Cosine
acos(a)	Inverse Cosine
tan(a)	Tangent
atan(a)	Inverse Tangent
atan2(a, b)	Arctangent
average(a, b, ...)	Average of arguments
clamp(a, lo, hi)	a if it is between lo and hi, otherwise lo or hi
clampmin(n, min)	clamp values below minimum
clampmax(n, max)	clamp values above maximum
copysign(t, t sign)
dim(t x, t y)
fma(t a, t b, t c)	Computes (a*b) + c
fmod(t, t)
fraction(t)
lerp(a, b, f)	Linear interpolation (a + (b - a) f)
min(a, b, ...)	Smaller of values
max(a, b, ...)	Larger of values
mid(a, b)	Average of a and b
noise(seed / x, y)	Generate 1D noise either from a seed or based on X/Y input.
round(n)	Round to integer
roundup(b), ceil(n)	Round up to integer
rounddown(b), floor(n)	Round down to integer
trunc(t)	Shorthand for truncate
truncate(n)	Truncate n places after decimal point.
whole(t)