| Display scaling
HIGH RESOLUTION Automatically finds the Y-range of the data and selects Y-axis scaling equal to the total range plus 5% in either direction. SCALE TO INCLUDE ZERO Selects a range that includes zero and the entire Y-range of data, and sets the tic marks at whole numbers or simple fractions. If the data are all positive or all negative, the scale will be set to include at least 110% of the data range, using zero as the minimum or maximum Y value, respectively.
NORMAL SCALING LabAnalyst's default scaling protocol. Selects a Y-axis scaling factor that includes the entire Y-range of the data, with tic marks set at whole numbers or simple fractions. If data include both positive and negative values, this is equal to 'SCALE TO ZERO'. If data are all positive or all negative, 'NORMAL SCALING' may select a smaller scale factor (i.e., higher resolution). MANUAL SCALING... Allows manual selection of minimum and maximum Y-values for the plot area. This is useful to optimize scaling for plot regions of particular interest. On may occasions, the automatic scaling options (NORMAL SCALING and SCALE TO ZERO) do not show areas of particular interest at sufficiently high resolution.
When the manual scaling window (shown at right) opens, it displays the current scaling values for the active channel. You can modify them as desired.
SET INTERACTIVELY... Lets you use the mouse and cursor in the plot area to set
the scaling limits, using this small window:
- Click the 'Upper limit' or 'Lower limit' button, then move the cursor line to the desired spot and click the mouse once. You can also expand a plot with a too-confining scale by clicking the 'Expand 2X' or 'Expand 3X' buttons. When done, click the 'done' or 'cancel' buttons. Clicking the plot area when the horizontal cursor line is not showing is the same as clicking the 'done' button.
When using manual or interactive scaling it's important to remember that the SAME scaling constraints will apply to all segments of the channel -- regardless of what data they contain. Manual scaling is switched off (and Normal scaling is switched on) whenever a new file is loaded. When you perform a baseline correction on a manually-scaled channel (either 'regular' manual scaling or interactive scaling), scaling is automatically reset to 'HIGH RESOLUTION' mode. This is because the baseline operation changes the position of the data, so manually-set limits are frequently completely outside the data range after baseline correction.
HIGH RESOLUTION SCALE TO INCLUDE ZERO NORMAL SCALING N
These have the same action as described above, except that they reset the scaling defaults for all channels (not just the active channel).