When your plot contains a large amount of data points, Origin automatically displays the graph with a reduced number of data points (in default,100×100 matrix cells for 3D; 3000 data points in 2D) – so called in **Speed Mode**. When the graph layer is presented in the Speed Mode, it is indicated by a **RED** layer icon at the top left corner of the graph, and a grey text “**Speed Mode is On**” inside the graph, as well. Please look at the sample screenshot at right. (In this example, I have set the reduced number of points to mere 20×20 to emphasize the effect of the Speed Mode.)

If you turn OFF the Speed Mode (from **Graph: Speed Mode** menu), you see the whole complete details from the original data as in the second graph. Thus, the advantages of the Speed Mode are:

1) The (re)drawing speed of the graph would be improved, and

2) It may improve the readability of the graph to hide the too much details (for example, when the data fluctuates too much by noise).

You should know that the Speed Mode is just a matter of how the graph is presented on the monitor – no modification or reduction of the data itself whatsoever. Thus, if you print or export the plot in Speed Mode, Origin outputs the all data points no matter the Speed Mode is either ON or OFF.

Then, can we get the print out, or the exported image with the reduced number of data points as in the Speed Mode on screen? Yes, you can.

Please see the next two screenshots of the Print dialog box, and the graph export dialog box. In the former dialog, you can specify the number of data points to be skipped when it is printed, and in the later case, you can choose whether the exported image follows the Speed Mode setting in graph, or on or off.

In contrast to the above Speed Mode control, you may also want to consider to reduce the actual number of data – not only to display, print, or export, but also to manipulate or analyze. Then, you have to look for other ways instead of Speed Mode which is just for the mere display purpose. In the case of matrix data for 3D, you can shrink it (**Matrix: Shrink** menu). In the case of the 2D data in a worksheet, there are various ways such as:

1) **Data Reduction tools**: There are various tools to reduce the number of data. For details, see: http://www.originlab.com/doc/Tutorials/Data-Reduction .

2) **Data Filtering**: You can filter data on a worksheet with index conditioning, e.g., **i-int(i/200)*200=0** for every 200-th point. For details, see: http://www.originlab.com/doc/Tutorials/Data-Filter

3) **Masking**: You can run the Worksheet Query tool (**Worksheet: Worksheet Query** menu) to select all data (with Select option in Output group) except every n-th row by the condition, e.g., **i-int(i/200)*200!=0** . Then you can right-click the selected **Mask: Apply** shortcut. Once masked, you can hide the masked data points from the **Mask** toolbar.

4) **Interpolation**: Origin’s interpolation tool can also reduce the number of data points at the evenly spaced X locations (therefore, the original data are not preserved), calculated by interpolation.

Finally, for the presentation of a graph with a large number of drop lines, there is a **Skip Points** option in the **Drop Lines** tab in the Plot Details dialog. You can see a sample plot and its option setting below:

You need to consider what is the best approach to reduce the number of data points among various methods, but the Speed Mode at first hand does the job immediately and readily when you made a plot.