Zooming in on a portion of a graph
Sometimes it is desireable to be able to zoom in on
a portion of a graph in order to find out details such
as the value(s) at the intersection of two plotted
equations. These types of points are of interest since
they are the set(s) of values that are the solution
to both equations.
Zooming Method 1:
1. Click on the graph so that it appears in the
solid boarder with handles. It also has numerical
values at the extremes of each of its axes in addition
to the usual values along each of the axes.
2. Click on the leftmost value for the horizontal
axis. A cursor appears in that location.
3. Press the Delete key to remove the present value of
10 and replace it with a placekeeper.
4. Type in 15
and press the
key. The leftmost value on the horizontal scale is
changed from the default value of 10 to 15. The graph
has now zoomed in on the portion of the data between
the values of 15 and 20.
Note: The same steps are used to zoom out
on a graph. However, the graph will only plot the
values which are defined by the original range variable
and the resulting values computed for the dependent
variable. It will not extrapolate the plot to the
Zooming Method 2:
1. Click on the graph
to select it.
2. In the Format menu at the top of the window, choose G
raph and then Zoom
This causes the X-Y dialog box to appear.
3. If needed, the dialog box can be repositioned,
using the mouse, to allow the complete graph to
4. Within the graph region, place the mouse at
a location which locates one corner of a box that
you want to draw to describe the region you want
5. Press and hold the mouse button down as you
define the box around the area to be magnified
by dragging the mouse through a diagonal path to describe
the region to be magnified. A dashed rectangle
appears as you drag the mouse to indicate the region.
6. If necessary, the region can be repositioned
by positioning the cursor in the dashed box,
pressing and hold the mouse button and move the mouse
to reposition the dashed rectangle.
Note that the coordinates of the corners of the
dashed box are displayed in the X-TY Zoom
dialog box and that they change as dashed box is moved.
7. Clicking on the Zoom button redraws the graph
within the dahed box as the full graph.
8. The limits of the axes are those of the dashed
box. However, they can be changed as described
in Zooming Method 1, above.
To unzoom a graph that has already been zoomed but which
the axis limits have not been changed.
1. Click on the graph to activate its graph region.
2. Choose G
raph => Zoom
from the F
menu to bring up the X-Y
3. Click on the U
button to get back to the previous level of zoom or
click on the Full View
button to see the original graph prior to any zooming.
To see a readout of the graph coordinates that make
up a trace:
1. Click on the graph region to select it.
2. Choose G
raph => Trace from the F
menu, or clic on the Trace button on the Graph
Palette, to show the X-Y Trace dialog box. Reposition
the box so that the entire graph can be
seen, if necessary. Note that the Track Data Points
box is checked.
3. In the graph region, click and drag the mouse
along the trace whose coordinates you want
to see. A dotted crosshair jumps from one point to
the next as you move along the trace.
4. If the mouse button is released, the left and
right arrrows can be used to move to the previous
or next data points. The up and down arrows move to
other traces on the same graph.
5. As the pointer reaches each point on the trace,
Mathcad displays the x and y values of that
point in the X-Value and Y-Value boxes.
6. The coordinate values of the last selected
point remain in the boxes. The crosshair remains
until you click outside the graph.
To copy a coordinate to
1. Click "Copy X "or "Copy Y".
The value can then be pasted into a math region or
a text region on the Mathcad worksheet,
into a spreadsheet, or into any other application
that allows pasting from the clipboard.
2. Click outside the graph or on the "Close"
button to make the crosshairs disappear.