SPLINE_READ

Use

<Reference_Spline
     id              = "301001"
     usrsub_dll_name = "c:\work\test.dll"
     file_name       = "c:\data\spring1.dat"
     block_name      = "spring_force">
</ Reference_Spline>

Format

Fortran Calling Syntax

SUBROUTINE SPLINE_READ (ID, FILE_NAME, BLOCK_NAME, ERRFLG)

C/C++ Calling Syntax

void STDCALL SPLINE_READ (int *id, char *file_name, int file_name_len, char *block_name, int block_name_len, int *errflg)

Python Calling Syntax

def SPLINE_READ(id, file_name, block_name):
    return errflag

MATLAB Calling Syntax

function errflg = SPLINE_READ(id, file_name, block_name)

Attributes

ID

[integer]

The user-defined Reference_Spline element identifier.

FILE_NAME

[CHARACTER*(*)]

An array of dimension 132 containing the FILE_NAME argument value.

BLOCK_NAME

[CHARACTER*(*)]

An array of dimension 132 containing the BLOCK_NAME argument value.

Output

ERRFLG

[logical]

The variable to indicate the status of SPLINE_READ reading the data. Using PUT_SPLINE, set it to TRUE if there are errors, and FALSE if there are no errors. A return value of TRUE causes MotionSolve to stop relevant computations.

Example

1. The following example demonstrates the SPLINE_READ user subroutine using the Python scripting language:

   def SPLINE_READ(id, file_name, block_name):
   
     x =6*[0.0]
     y =6*[0.0]
   
     x[0] =0.0
     x[1] =0.3
     x[2] =0.5
     x[3] =1.0
     x[4] =1.5
     x[5] =2.0
   
     y[0] =0.0
     y[1] =0.0
     y[2] =0.0
     y[3] = -0.05
     y[4] = -0.15
     y[5] = -0.3
    
     z =0.0
   
     errflg = py_put_spline(id, x, y, z)
   
     return errflg

2. In the example below, the SPLINE_READ subroutine is used to populate a Reference_Spline model element with values that are read from an external file data.txt.
   1. The model element:

      <Reference_Spline
           id                  = "301001"
           label               = "Excite"
           interpreter         = "Python"
           script_name         = "read_curve.py"
           usrsub_fnc_name     = "SPLINE_READ"
           file_name           = "data.txt"
           block_name          = "dummy"
           linear_extrap       = "TRUE"
      />

   2. The external file data.txt contains a comma separated list of x, y values as shown below:

        0,     0
        0.1,   4.045084972
        0.2,   4.755282581
        0.3,   1.545084972
        0.4,   -2.938926261
        0.5,   -5
        0.6,   -2.938926261
        0.7,   1.545084972
        0.8,   4.755282581
        0.9,   4.045084972
        1,     1.07195E-14
        1.1,   -4.045084972
        1.2,   -4.755282581
        1.3,   -1.545084972
        1.4,   2.938926261
      …

   3. The user subroutine SPLINE_READ is written in the Python scripting language and is shown below:

      #
      # This is an example for a spline read
      #
      def SPLINE_READ(id, file_name,block_name):
          x_ = []
          y_ = []
      
      # Open the external file for reading
          f = open(file_name, 'r')
      
      # Loop throught the file contents to get x,y values
        while 1:
         line = f.readline()
         if not line:
            break
         cols = line.split(',')
         x_.append(float(cols[0]))
         temp = cols[1].split('\n')
         y_.append(float(temp[0]))
         z_ = 0.0
      
      # Use py_put_spline to put the x, y, z values into reference_spline
        errflg = py_put_spline(id, x_, y_, z_)
        return errflg