Welcome to Adams/Solver Subroutines - Kxcad.net

Input Arguments
Welcome to Adams/Solver Subroutines
x A double-precision variable that specifies the independent variable.
x0 A double-precision variable that specifies the x value at which the step
function begins.
h0 A double-precision variable that specifies the value of the function before
the step.
x1 A double-precision variable that specifies the x value at which the step
function ends.
h1 A double-precision variable that specifies the value of the function after the
step.
iord An integer variable that defines the order of the derivative that STEP is to
return. The order is usually zero, but it can be one or two.
Output Arguments
errflg A logical (true or false) variable that STEP returns to the calling
subroutine. If STEP detects an error in the subroutine call statement, it sets
errflg to true before it returns errflg to the calling subroutine.
value A double-precision value the subroutine returns. The value returned
depends on IORD as follows:
Extended Definition
Figure 1 below demonstrates the step function. For a comparison of STEP and STEP5, and the first
derivatives of STEP and STEP5, see:
• STEP (C++ or FORTRAN) function
• STEP5 (C++ or FORTRAN) function
IORD: Value:
0 Value of the function.
1 Partial derivative of the function with respect
to x.
2 Second partial derivative of the function with
respect to x.
F( x)
∂ F
-----
∂ x
∂ 2 F
∂ x 2
--------
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