general Constants float_epsilon hoc_ac_ hoc_obj_
predeclared-variables
float_epsilon = 1e-11Allows somewhat safer logical comparisons and integer truncation for floating point numbers. Most comparisons are treated as true if they are within float_epsilon of being true. eg.
for (i = 0; i < 1; i += .1) {
print i, int(10*i)
}
float_epsilon = 0
// two bugs due to roundoff
for (i = 0; i < 1; i += .1) {
print i, int(10*i)
}
predeclared-variablesA variable used by the graphical interface to communicate with the interpreter. It is very volatile. It sometimes holds a value on a function call. If this value is needed by the user it should be copied to another variable prior to any other function call.
predeclared-variables
hoc_obj_[0]hoc_obj_[1]
predeclared-variablesThe following mathematical and physical constants are built-in:
"PI", 3.14159265358979323846,
"E", 2.71828182845904523536,
"GAMMA",0.57721566490153286060, /* Euler */
"DEG", 57.29577951308232087680, /* deg/radian */
"PHI", 1.61803398874989484820, /* golden ratio */
"FARADAY", 96484.56, /*coulombs/mole*/
"R", 8.31441, /*molar gas constant, joules/mole/deg-K*/
The FARADAY is a bit different than the faraday of the units database. The faraday in a .mod mechanism is 96520.