After computing with arrays in Mathcad, your resulting arrays may be large and unwieldy when displayed. Mathcad therefore displays matrices and vectors having more than nine rows or columns as scrolling output tables rather than as matrices or vectors. Figure 10-7 shows an example
A scrolling output table displays a portion of an array. To the left of each row and at the top of each column, there is a number indicating the index of the row or column. Use these row and column headers to determine the index of a particular value in the table
If your results extend beyond the table, a scroll bar will appear along the appropriate edge of the table. You can scroll through the table using these scroll bars just-as you would scroll through any window
Another way to view more of a resulting array is to enlarge the table. To resize a scrolling output table
• Click the mouse just outside the equation region in which the scrolling output table appears. This anchors one comer of the selection rectangle.
• Press and hold down the mouse button. With the button still held, drag the mouse across the scrolling output table. A selection rectangle emerges from the anchor point.
• When the selection rectangle just encloses the equation region, release the mouse button.
• Move the mouse pointer to the right or bottom edge of the selection rectangle. It will change to a double headed arrow.
• Press and hold down the mouse button. With the mouse button still pressed, move the mouse. The scrolling output table will be stretched in the direction of the motion.
• Once the scrolling output table is the right size, release the mouse button. Click outside the selection rectangle to deselect the equation region.
In addition to being able to resize and scroll through a scrolling output table, you can copy one or more values from it and paste them into another part of your worksheet or into another Windows application. For information on copying results from a scrolling output table, see the section “Copying numerical results” in Chapter 7.
Changing the display of arrays
Although matrices and vectors having more than nine rows or columns are automatically displayed as scrolling output tables, you can have Mathcad display them as matrices. To do so:
• Click on the scrolling output table.
• Choose Number from the Format menu.
• Click on the box beside “Display as Matrix.” The box should now be checked.
• Click the “OK” button.
To display all the matrices and vectors of results in your worksheet as matrices regardless of their size:
• Click on an empty part of your worksheet.
• Choose Number from the Format menu.
• Click on the box beside “Display as Matrix.”
• Make sure the “Set as worksheet default” radio button is filled and click “OK”.
Graphical display of matrices
In addition to looking at the actual numbers making up an array, you can also see a graphical representation of those same numbers. There are three ways to do this:
For an arbitrary array, you can use the various three dimensional plot types discussed starting at Chapter 22, “Surface Plots.”
• For an array of integers between 0 and 255, you can look at a grayscale image by choosing Picture from the Insert menu and entering the array’s name in the placeholder.
• For three arrays of integers between 0 and 255 representing the red, green, and blue components of an image, by choosing Picture from the Insert menu and entering1 the arrays’ names, separated by commas, in the placeholder.
An example of viewing a matrix as a grayscale image is shown in Figure 18-19 of Chapter 18, “Programming.” See Chapter 28, “Importing and Exporting Graphics,” for more on viewing a matrix (or three matrices, in the case of a color image) in the picture operator.