| iTool User's Guide: Manipulating the Display |

## Scaling

Two types of scaling are possible: constrained scaling and unconstrained scaling.

#### Constrained Scaling

Constrained scaling permits scaling of only one dimension while preserving the other dimensions.

##### Constrained Scaling of 2-D Objects

To scale one dimension of a 2-D object, click on the object so that eight small selection-boxes appear at each corner of the object and also midway along each side of the object. Then position the mouse onto one of these boxes so that the mouse pointer changes to a four-headed arrow pointer (see the following figure). Drag the mouse in the desired direction to scale the object in the selected dimension.

Figure 4-2: Resizing a 2-D Plot

Figure 4-2: Resizing a 2-D Plot

##### Constrained Scaling of 3-D Objects

Two types of constrained scaling are available for 3-D objects: multiple-axis scaling and single-axis scaling.

The multiple-axis scaling mouse pointer for 3-D objects is a three-headed arrow displayed when the mouse pointer is positioned over a corner of a 3-D object's data space. Dragging the constrained scaling pointer scales the object a fixed distance along all axes in the direction of the drag.

Figure 4-3: Constrained Scaling

Figure 4-3: Constrained Scaling

The single-axis scaling pointer for 3-D objects is a two-headed arrow , displayed when the pointer is positioned over an axis "whisker" in a 3-D image. Dragging an axis "whisker" scales the object only in the direction of the arrows.

Figure 4-4: Resizing a 3-D Surface

Figure 4-4: Resizing a 3-D Surface

#### Unconstrained Scaling

Unconstrained scaling allows you to scale all dimensions of an object at once from any point within the object. Unconstrained scaling is different for 2-D and 3-D objects.

##### Unconstrained Scaling of 2-D Objects

Unconstrained scaling of 2-D objects occurs when a corner of the data set bounding box is dragged. The mouse pointer changes to an unconstrained scaling pointer , and the object is scaled in the direction of the drag.

Figure 4-5: Unconstrained Scaling of a 2-D Plot

Figure 4-5: Unconstrained Scaling of a 2-D Plot

##### Unconstrained Scaling of 3-D Objects

Unconstrained scaling of 3-D objects occurs when a single side of the data set bounding box is dragged. The mouse pointer changes to an unconstrained scaling pointer , and the object is scaled along the dimensions of the selected side.

Figure 4-6: Unconstrained Scaling of a 3-D Surface

Figure 4-6: Unconstrained Scaling of a 3-D Surface

IDL Online Help (March 01, 2006)