The modify commands change the x or y (or both) coordinates of a single data point by moving the edit cursor with the mouse. After a modify command, the the lengths of the x and y vectors normally don't change ... however there are two exceptions to this. The first is called the "delete mode" which is activated by dragging the edit cursor to any point outside the axis boundary. The point dragged will be removed causing the lengths of the x and y vectors to decrease by one. The 2nd exception is called the "insert mode". The insert mode is activated by dragging the edit cursor with the right mouse button instead of the usual left button. With the insert mode, the lengths of the x and y vectors will both increase by one. | |
With the range commands the length of the x and y vectors remain the same. The range commands allow you to modify many consecutive data elements at once. All the data points between the current cursor location and the location modified during the previous data editing command are modified so that all these points lie on a straight line connecting the two end locations. For this to work, the previously edited point and the current cursor location must both lie on the same line. If this is not true, then the Range commands behave just like the Modify commands described above. You can recognize whether the range operation or the modify operation is in progress based on the shape of the edit cursor (See cursor shapes table below). |
![]() ![]() Modify↑↓ Range↑↓ |
These are perhaps the two most commonly used of the data editing menus. As soon as you select the editing mode, the regular data cursor disappears and is replaced by an editing cursor with a different shape. (See data editing cursor shapes below). Then you can grab the edit cursor with the mouse and drag it to the desired location. However you will only be able to move the cursor up and down (i.e. only the y coordinate is allowed to change). This is useful because in many data sets, the independent variable (x) represents a specific chosen set that you want to keep fixed. As soon as you release the mouse button (after the edit cursor has been dragged to its new location) the edit command will take effect, the edit cursor will disappear, and the normal data cursor will reappear. The cursor then reverts to its usual data exploration function, and to edit another data point you must right click yet again on the Ycursor edit box and select the desired data edit operation. This back and forth operation (which I will call the "normal editing mode" is convenient when you just have a few data points to modify, but can become cumbersome when you want to edit many data points in succession. In that situation you can switch to "persistent editing mode". (The persistent editing mode applies only to the three Modify selections and does not apply to any of the Range selections). To enable the persistent editing mode for Modify up/down, bring up the data editing menu as usual, but then instead of left clicking on the Modify up/down selection, click on it with the right mouse button. The label in front of the Ycursor edit box (gray) normally contains the letter "y" (as shown to the left) but this label will switch to the delta symbol (shown to the left) which indicates that you are now in persistent editing mode. Once in this persistent mode, you can continue to modify as many points on the graph as you want (including insert and delete operations) without having to open the data editing menu each time. The only drawback is that you have to forgo the usual data exploration features of the cursor, however you can restore the default mode by double RIGHT clicking on the Ycursor edit box. (at which point the Ycursor label changes from the delta back to the "y"). |
![]() Modify↔ Range↔ |
These two menu options behave identically to the two commands described above except for the fact that with the mouse you can only drag the cursor left or right (i.e. only the x coordinate is allowed to change). It is far more common to want to change the y coordinate (using the selections above) or to use the selections below to have the freedom to move the point anywhere (modifying both coordinates), however the left/right option is included for completeness. You can also select this option with the persistent editing mode by right clicking on the Modify left/right option. The gray "y" label of the Ycursor editbox changes to a ">" greater than sign (as shown at the left) to indicate the persistent mode is enabled. Again, you can restore the normal editing mode by double RIGHT clicking on the Ycursor edit box, which will cause the label to revert to "y" indicating the normal editing mode. |
![]() Modify Range |
When using these last two menu options you can use the mouse to drag the edit cursor anywhere (i.e. you can change both the x and y coordinates of the point. You can select this option with the persistent editing mode by right clicking on the Modify option. The gray "y" label of the Ycursor editbox changes to a solid diamond symbol (as shown at the left) to indicate the persistent mode is enabled. Again, you can restore the normal editing mode by double RIGHT clicking on the Ycursor edit box, which will cause the label to revert to "y" indicating the normal editing mode. |
The CursorID associated with the edited trace | |
A number from 1 to 6 which identifies which data edit command
is being used (in the order that they appear in the popup): 1: Range 2: Range Left/Right 3: Range Up/Down 4: Modify 5: Modify Left/Right 6: Modify Up/Down |
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The handle of the cursor object associated with the modified data. | |
For internal use. (This saves the cursor marker shape and size so that the normal cursor can be restored when the data edit operation is complete.) | |
For internal use. (This saves the edited trace x/y data so that it can be restored by the undo function (right clicking on the "Cancel" option) | |
For internal use. (This saves the position index and trace number of the previously edited trace - information is needed for the modify range operations.) | |
The position index of the cursor into the edited trace |
plt xleft EDIT 1; | Enter data editing (using last used editing mode) |
plt xleft EDIT 2; | Open up Yedit popup menu |
plt xleft EDIT 5; | Exit data editing mode |
plt xleft Yedit 4; | Cancel data editing mode |
plt xleft Yedit 5; | Enter data edit mode (Range) |
plt xleft Yedit 6; | Enter data edit mode (Range left/right) |
plt xleft Yedit 7; | Enter data edit mode (Range up/down) |
plt xleft Yedit 8; | Enter data edit mode (Modify) |
plt xleft Yedit 9; | Enter data edit mode (Modify left/right) |
plt xleft Yedit 10; | Enter data edit mode (Modify up/down) |
plt xright Yedit 8; | Enter persistent data edit mode (Modify) |
plt xright Yedit 9; | Enter persistent data edit mode (Modify left/right) |
plt xright Yedit 10; | Enter persistent data edit mode (Modify up/down) |