Module 2 Array Parameters

2. Array Parameters Array Parameters are parameters that can take on multiple values. They can be 1-D, 2-D, or 3-D. 1-D: m rows x 1 column 2-D: m rows x n columns 3-D: m rows x n columns x k planes 17.1 -47.6 -5.2 25.0 107.9 814 17 386 1057 -47 704 1033 -52 348 7141 25 -66 622 107 111 AA = BB = CC = 5x1 array 5x3 array mxnx3 array October 30, 2001 Inventory #001571 2-2

...Array Parameters In this chapter, we will discuss how to define array parameters and how to perform operations among them. Topics covered: A. Types of Array Parameters B. How to Define C. Retrieving Database Information D. Array Operations E. Workshop October 30, 2001 Inventory #001571 2-3

Array Parameters A. Types of Array Parameters There are three types of array parameters: Array Table Character Type array is a standard 1-D, 2-D, or 3-D matrix of numeric values, such as BB shown here. BB(2,3) = 704 BB(3,1) = 1033 etc. 814 17 386 1057 -47 704 1033 -52 348 7141 25 -66 622 107 111 5x3 array BB = October 30, 2001 Inventory #001571 2-4

Array Parameters ...Types of Array Parameters Type table is similar to array, except that its row, column, and plane indices can be real numbers, allowing you to interpolate values. Requires the “zeroth” row, column, and plane to be filled with numbers. Useful to define time-dependent loads and other similar functions. Primary variables include X, Y, Z, temperature, velocity, pressure and time. For example, the table array FORCE could represent a force-vs-time function, with the zeroth column representing time values. FORCE(0.4) = 279.9996 FORCE(6.5) = 560.0 FORCE(8.9) = 119.25 etc. October 30, 2001 Inventory #001571 2-5

Array Parameters ...Types of Array Parameters A character array is a 1-D, 2-D, or 3-D matrix of alphanumeric strings. Useful for storing file names, DOF labels, etc. Each string can have up to eight characters. JOB1 JOB2 JOB3 JOB4 JOB5 UX UY UZ ROTY ROTZ jobs = dofs = October 30, 2001 Inventory #001571 2-6

Array Parameters B. How to Define Two steps to define an array parameter: 1. Specify name, type and dimension. Utility Menu > Parameters > Array Parameters > Define/Edit > Add or *DIM command. Example: *dim,aa,array,4 ! 4x1x1 array *dim,force,table,5 ! 5x1x1 table *dim,bb,array,5,3 ! 5x3x1 array *dim,dofs,char,6 ! 6x1x1 character array parameter name can not exceed 32 characters October 30, 2001 Inventory #001571 2-7

Array Parameters ...How to Define 2. Fill in the array values. Utility Menu > Parameters > Array Parameters > Define/Edit > Edit Or *VEDIT command Or “=”command. Example: bb(1,1)=11,21,31,41,51 bb(1,2)=12,22,32,42,52 bb(1,3)=13,23,33,43,53 October 30, 2001 Inventory #001571 2-8

Array Parameters ...How to Define For table type arrays, you must fill in values for the zeroth locations. Otherwise, their values will default to the “tiny” number 7.8886E-31. For example: force(1,1)=0,560,560,238.5,0 force(1,0)=1E-6,0.8,7.2,8.5,9.3 force(0,1)=0 October 30, 2001 Inventory #001571 2-9

Array Parameters ...How to Define For character arrays, there is no graphical way to fill in the strings. Use the “=”command to type in the values, then use *STAT to list them. Each string must be enclosed in single quotes. Example: dofs(1) = ‘ux’, ‘uy’, ‘uz’, ‘rotx’, ‘roty’, ‘rotz’ *stat,dofs October 30, 2001 Inventory #001571 2-10

Array Parameters ...How to Define There are many other ways to fill arrays: Predefined functions in *VFILL command (Utility Menu > Parameters > Array Parameters > Fill) ramp function random function etc. Read data from a file: *VREAD for arrays *TREAD for tables Or Utility Menu > Parameters > Read from File Retrieve data from the database (discussed next). October 30, 2001 Inventory #001571 2-11

Array Parameters C. Retrieving Database Information Just as *GET retrieves scalar data from the database, you can use *VGET to retrieve array information. Or Utility Menu > Parameters > Get Array Data First dimension the array, then retrieve the data. Example: *dim,dispval,array,20,3 ! 20x3 array *vget,dispval(1,1),node,1,u,x ! UX of nodes 1-20 in column 1 *vget,dispval(1,2),node,1,u,y ! UY in column 2 *vget,dispval(1,3),node,1,u,z ! UZ in column 3 October 30, 2001 Inventory #001571 2-12

Array Parameters …Retrieving Database Information Other types of array information you can retrieve: nodal and keypoint coordinates (in the active CSYS) attributes of elements, volumes, areas, etc. select status of entities (1 if selected, 0 if not selected) nodal stresses, strains, thermal gradients, thermal flux, etc. element table data and so on… October 30, 2001 Inventory #001571 2-13

Array Parameters D. Array Operations Once you have defined array parameters, you can perform a variety of operations among them. Utility Menu > Parameters > Array Operations Or *VFUN, *VOPER, *VSCFUN, *VWRITE, etc. October 30, 2001 Inventory #001571 2-14

Array Parameters ...Array Operations *VFUN operates on a single array parameter. *vfun,b(1),sin,a(1) will result in b(j)=sin(a(j)) Other operations include: natural log, common log, exponential Square root, sort, copy Conversion from local to global coordinates and vice-versa Tangent and normal vectors to a path etc. October 30, 2001 Inventory #001571 2-15

Array Parameters ...Array Operations *VOPER operates on two array parameters. *voper,c(1),a(1),sub,b(1) will result in c(k)=a(k)-b(k) Other operations include: addition, subtraction, multiplication, division min, max, logical operations derivatives, integrals dot and cross products October 30, 2001 Inventory #001571 2-16

Array Parameters ...Array Operations *VSCFUN determines properties of an array parameter. *vscfun,maxval,max,a(1) will result in a scalar parameter maxval = max(a(i)) Other operations include: sum of all the elements of an array statistical quantities such as mean, median, standard deviation, variance and rms min/max, index location of min/max index locations of first and last non-zero entry October 30, 2001 Inventory #001571 2-17

Array Parameters ...Array Operations *VWRITE writes data to a file in a formatted sequence. Utility Menu > Parameters > Array Parameters > Write to File Example: *cfopen,wing,dat *vwrite (/,3x,’Node Number’,4x,’Temperature’,/) *vwrite,nnum(1),tval(1) (5x,f6.0,6x,e14.8) *cfclose will create a file called wing.dat with the nnum and tval arrays written in specified format. October 30, 2001 Inventory #001571 2-18

Array Parameters ...Array Operations There are many, many more array operations available. Please refer to your APDL Programmer’s Guide for details. October 30, 2001 Inventory #001571 2-19

Array Parameters E. Workshop Refer to your Workshop Supplement for instructions on: W1. Axisymmetric Wheel October 30, 2001 Inventory #001571 2-20