PRESENT CONTOUR Mode [Range]

                        

This command draws contours of result values.

Mode Range Comments

DATUM v1 STEPS v2 Using v1 as a datum, values in steps of + and - v2 from this datum are contoured.

v1 LEVELS n `n' contours will be drawn at equal increments above and below the datum `v1'. The increment is chosen according to the current minimum and maximum values.

LEVELS [n] `n' contours will be drawn at equal increments between the current minimum and maximum result values. If `n' is not specified a default value (initially 10) is used (see note 5).

VALUES v1 [v2]... Each value will be contoured.

FROM v1 TO v2 STEPS v3 With `v1' as the 1st contour, contours will be drawn at `v3' increments until `v2'.

v1 TO v2 LEVELS n `n' contours (inclusive of a contour at `v1' and `v2') will be drawn at equal increments between `v1' and `v2'.

 

Figure 2.98: Filled contours

Examples:

1.

PRESENT CONTOUR DATUM 0.0 STEPS 1.0

If the minimum value were 7.5 and the maximum 10.2 then values 8.0, 9.0 and 10.0 would be contoured.

2.

PRESENT CONTOUR LEVELS 20

20 equal increment contours will be drawn from the minimum to the maximum value of the current result component. The actual minimum and maximum values are not contoured.

3.

PRESENT CONTOUR VALUES 1.1 1.2 1.5

Contour corresponding to the values 1.1, 1.2 and 1.5 will be displayed.

4.

PRESENT CONTOUR FROM 2.5 TO 3.3 STEPS 0.1

Contours will be displayed at 0.1 intervals in the specified result range, e.g. 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3.

 

Figure 2.99: Line contours

Notes:

1.

Effect of view mode when contouring element faces
Where the faces of elements are to be contoured (see PRESENT OPTIONS CONTOUR FILL and PRESENT OPTIONS CONTOUR LINES), with view modes (see: VIEW) other than VIEW HIDDEN, the faces of the model will be contoured in the order in which the elements occur in the database, so with some models, the faces at the back of the model may be contoured after faces nearer to the observer which will produce a confusing picture. The effect of contouring element faces with certain view modes is as follows:

View Mode Region Contoured

EDGES With 2D and shell models all element faces in the current results set are contoured. With 3D solid models, because no individual element faces are defined, an error message will be generated.

HIDDEN All drawn element faces in the results set are contoured. The order of contouring ensures a full hidden line contour picture.

MESH All drawn element faces in the results set are contoured. Note that with 3D solid models `internal' element faces are drawn and so will be contoured.

2.

Determination of Maximum and Minimum Values
The default condition is that the maximum and minimum values used by the contouring algorithms refer to the current results set. If no results set has been defined the results set equates to the current model sub-set, which by default is the whole model. The user can explicitly request that the maximum and minimum values used refer to the whole model by entering the command RESULTS RANGE GLOBAL; or refer to the current results set by entering the command RESULTS RANGE LOCAL. If a cross-section has been defined the command RESULTS RANGE LOCAL SECTION will request that the maximum and minimum values used refer to the cross-section.

3.

Interpolation of Values
The values used to produce contours of nodal, element nodal or Gaussian results are calculated by linear interpolation from the values at the nodal points. (When contouring Gauss point values, the vertex node of an element will have been given the result value of its nearest Gauss point. Values at element mid-side nodes are taken as the average of the two appropriate vertex nodes. However, if the mesh is being viewed in filled or shaded mode then only one value per element will be used. This limitation may be overcome by use of the `RESULTS CALCULATE EXTRAPOLATE' command.)

When contouring element invariant values no interpolation is performed (this is an option with other values, see PRESENT OPTIONS CONTOUR); and each element is represented by a single colour.

4.

Annotation
When line contours are being displayed (see: PRESENT OPTIONS CONTOUR LINES) the default condition is that each contour line will be annotated, on average, every every fifth segment of its length. If the number of contour lines exceeds 26 then some contour lines will not be annotated. The user may alter the frequency of annotation (see: PRESENT OPTIONS CONTOUR LINES KEYLINE).

5.

Changing defaults
The default for PRESENT CONTOUR LEVELS is that 10 contours will be drawn. The default may be changed via the command PRESENT OPTIONS CONTOUR LEVELS DEFAULT n

See also the following commands

'PRESENT OPTIONS CONTOUR'
'RESULTS CALCULATE EXTRAPOL'
'RESULTS RANGE'