If you are inside a loop the variable LOOP is also available. The user accessible variable A1 through A5 can be given values using the ASSIGN command. Any variables specified using the VARIABLE command may also be used. These also have precedence over the built in constants. For example, a user defined variable named ``C'' can have the value set using ASSIGN and need not be the speed of light.
Very simple arithmetic operations are also possible in the input.
Only two operands are allowed and there must be no spaces between
these and the operator. Examples are:
Simple functions of arguments are also possible. For example,
these are valid arguments:
As with XFUNCTION etc. trigonometric functions assume degrees.
Functions presently available include:
evaluated as a single value: the speed of light squared.
this is equivalent to the expression above.
evaluated as a single value: 3.
because of the space this will be evaluated as two
numbers: 1 and 2.
evaluated as three numbers: 0.5, -0.5 and the product of the mean of
the data set and the user assigned variable A1.
sin, cos, tan, sqrt, square, cbrt, cube, log, loge, log2, exp, exp10, abs,
factorial, inverse, asin, acos, atan, sinh, cosh, tanh,
asinh, acosh, atanh, j0, j1, round (IEEE rounding),
ceil and floor. In addition to these data values are also available
as ``functions'' i.e. x, y, z, xerr and yerr. x{3} for example is
the ``X'' value of the 3rd data point. The results of least squares
fits are available via fitvalue and fiterror. e.g. fitvalue{2}
is the result of the fit for parameter no. 2. It is advised not
to directly use fitvalue and fiterror as input to the CURFIT
command.