KNOWLEDGEBASE - ARTICLE #1105
What functions can I use when constructing user-defined equations or transforms?
You may use any of these functions when constructing user-defined models. If you use a bessel, beta, gamma, or atan2 function, the order of parameters is backwards in Prism 5.00, 5.01 and 5.0b.
| Function | Explanation | Excel equivalent |
| abs(k) | Absolute value. If k is negative, multiply by -1. | abs(k) |
| arccos(k) | Arccosine. Result is in radians. | acos(k) |
| arccosh(k) | Hyperbolic arc cosine. | acosh(k) |
| arcsin(k) | Arcsine. Result is in radians. | asin(k) |
| arcsinh(k) | Hyperbolic arcsin. Result in radians. | asinh(k) |
| arctan(k) | Arctangent. Result is in radians. | atan(k) |
| arctanh(k) | Hyperbolic tangent. K is in radians. | atanh(k) |
| artctan2(x,y) | Artangent of y/x. Result is in radians. | atan2(x,y) |
| besselj(n,x) | Integer Order J Bessel, N=integer | besselj(x,n) |
| bessely(n,x) | Integer Order Y Bessel, N=integer | bessely(x,n) |
| besseli(n,x) | Integer Order I Modified Bessel, N=integer |
besseli(x,n) |
| besselk(n,x) | Integer Order K Modified Bessel, N=integer |
besselk(x,n) |
| beta(j,k) | Beta function. | exp(gammaln(j) +gammaln(k) -gammaln(j+k)) |
| binomial(k,n,p) | Binomial. Probability of k or more “successes” in n trials, when each trial has a probability p of “success”. | 1 - binomdist(k,n,p,true) + binomdist(k,n,p,false) |
|
chidist(x2,v) |
P value for chi square equals x2 with v degrees of freedom | chidist(x2,v) |
| ceil(k) | Nearest integer not smaller than k. Ceil (2.5)=3.0. Ceil(-2.5)=2.0. |
(no equivalent) |
| cos(k) | Cosine. K is in radians. | cos(k) |
| cosh(k) | Hyperbolic cosine. K is in radians. | cosh(k) |
| deg(k) | Converts k radians to degrees. | degrees(k) |
| erf(k) | Error function. | 2*normsdist(k*sqrt(2))-1 |
| erfc(k) | Error function, complement. | 2-2*normsdist(k*sqrt(2)) |
| exp(k) | e to the kth power. | exp(k) |
| floor(k) | Next integer below k. Floor(2.5)=2.0. Floor(-2.5)=-3.0. | (no equivalent) |
| fdist(f,v1,v2) | P value for F distribution with V1 degrees of freedom in the numerator and V2 in the denominator. | fdist(f,v1,v2) |
| gamma(k) | Gamma function. | exp(gammaln(k)) |
| gammaln(k) | Natural log of gamma function. | gammaln(k) |
| hypgeometricm(a,b,x) | Hypergeometric M. | (no equivalent) |
| hypgeometricu(a,b,x) | Hypergeometric U. | (no equivalent) |
| hypgeometricf(a,b,c,x) | Hypergeometric F. | (no equivalent) |
| ibeta(j,k,m) | Incomplete beta. | (no equivalent) |
| if(condition, j, k) | If the condition is true, then the result is j. Otherwise the result is k. See next section below. | (similar in excel) |
| igamma(j,k) | Incomplete gamma. | (no equivalent) |
| igammac(j,k) | Incomplete gamma, complement | (no equivalent) |
| int(k) | Truncate fraction. INT(3.5)=3 INT(-2.3) = -2 | trunc() |
| ln(k) | Natural logarithm. | ln(k) |
| log(k) | Log base 10. | log10(k) |
| max(j,k) | Maximum of two values. | max(j,k) |
| min(j,k) | Minimum of two values. | min(j,k) |
| j mod k | The remainder (modulus) after dividing j by k. | mod(j,k) |
| psi(k) | Psi (digamma) function. Derivative of the gamma function. | (no equivalent) |
| rad(k) | Converts k degrees to radians. | radians(k) |
| sgn(k) | Sign of k. If k>0, sgn(k)=1. If k<0, sgn(k)= -1. If k=0, sgn(k)=0. |
sign(k) |
| sin(k) | Sine. K is in radians. | sin(k) |
| sinh(k) | Hyperbolic sine. K is in radians. | sinh(k) |
| sqr(k) | Square. | k*k |
| sqrt(k) | Square root. | sqrt(k) |
| tan(k) | Tangent. K is in radians. | tan(k) |
| tanh(k) | Hyperbolic tangent. K is n radians | tanh(k) |
| tdist(t,v) | P value (one-tailed) corresponding to specified value of t with v degrees of freedom. T distribution. | tdist(t,v,1) |
| zdist(z) | P value (one-tailed) corresponding to specified value of z. Gaussian distribution. | normsdist(z) |