e is the base of the natural logarithm.e without arguments returns the scalare.e(N) returns a square matrix ofe of sizeN.e(N, M, ...) where the arguments are dimensions of some matrix ofe.e(..., CLASS) whereCLASS is an optional argument that specifies the return type,double orsingle.eps is the machine precision and returns the relative spacing between any floating point number and the next representable number. This value is system dependent.eps returns the value ofeps(1.0).eps(X) returns the spacing between X and the next value.eps with more than one argument is treated likee with the matrix value beingeps(1.0).epi is the ratio of the circumference to the diameter of any circle.I is the imaginary unit defined soI^2 = -1.Inf is used for values that overflow the standard IEEE floating point range or the result of division by zero.NaN is used for various results that are not well defined or undefined. Note thatNaN never equals otherNaN values. Use the functionisnan to check forNaN.realmax is the largest floating point value representable.realmin is the smallest positive floating point value representable.floor(X) andceil(X) return the highest integer not greater thanX or lowest integer not less thanX, respectively.round(X) andfix(X) return the integer closest toX or truncateX towards zero, respectively.rem(X,Y) andmod(X,Y) returns x - y * fix( x ./ y ) or x - y * floor( x ./ y ), they are the same except when dealing with negative arguments.hypot(X, Y) returns the length of the hypotenuse of a right-angle triangle with the adjacent and opposite of sizeX andY. abs(X) return absolute of x. sign(X) return sign of the x (-1, 0 or +1).cos(X),sin(x) andtan(X) — the elemental functions that we all know and love. They take their arguments in radians.acos(X),asin(X) are the inverses ofcos andsin and are able to compute arguments not contained in the range [-1,1].atan(X) andatan2(Y, X) are the 2 available inverses of tan.atan is a simple inverse whereasatan2 takes 2 arguments and returns an angle in the appropriate quadrant. More information onatan2 can be foundhere.atan2 and they will work in degrees rather than radians. For example:asind(0.3) = asin(0.3*180/pi) exp(x), exponential function of x log(x), natural logarithmic of x, loge NOT log10cosh(X),sinh(X) andtanh(X) are analog to their more prosaic counterparts but deal with the unit hyperbola instead of the unit circle. They also take their arguments in radians.acosh(X),asinh(X) andatanh(X) are the inverses ofcosh,sinh andtanh.