Last Update: 1/5/2018
The default Format (Text & Numeric, Numeric, etc.) of a column is Text & Numeric. When you enter or import text values into a column, Origin will recognize them as such. When these values get plotted as the X values, Origin will plot against row number, meaning a start value of 1 and an increment of 1. Each corresponding text value is then used to label each major tick.
From the graph, if you double-click on these tick labels to open the Axis dialog box, you'll see that the Type of the tick labels is Text from dataset and the dataset name listed is the name of that X column.
If you had a mix of text and numeric values in your X column, depending upon the percentage of each, Origin will either plot all values as text or it will plot the numeric values and treat the text as a missing values. If most data is numeric, the text will be treated as missing value and therefore the corresponding point will not show in graph. If you do want it to show and appear at certain x position, you will need to replace the text with numeric x value. Then add the text as special tick label.
Keywords:missing, tick, labels