---
description: 'Quick start guide: how-to and cheatsheet'
---

# If you're new to Igor Pro

## Intro

Igor data files are called "waves". This is a quite universal format to store data that can be one-, two- or more-dimensional. The wave is more than just a multidimensional matrix with numbers, it also stores the units and dimensions for each axis, so for ARPES data you can operate directly in terms of energy and angle values instead of constantly referring to point numbers.

A lot of useful info can be found in Igor Help files.

## Loading procedures

First open Igor Pro (64-bit), then drag and drop the procedure files (click and hold mouse button on the icon, then move it to the Igor window while keeping the mouse button pressed). In the procedure window press "Compile", if compilation process is successful, "Compile" button will become inactive. Then you can either fold procedure windows or press cross to close them and (when asked), select "Hide" (not "Kill"!).

## Loading data

After you have all the necessary procedures, you can drag and drop waves into Igor window. Some of the waves may be automatically displayed.

## Useful keyboard shortcuts

* Ctrl+I: brings graph cursors, you can use them to measure features' sizes in the image/graph. (First click on the window you want to work with)
* Ctrl+J: brings the command line panel
* Ctrl+B: brings data browser panel&#x20;
* Ctrl+A: Reset image view to see the whole image (to reverse zooming in)
* Ctrl+D: duplicates a wave in the Data Browser (e.g. if you want to try to modify the wave, but keep the original as a backup)

## Simple calculations

To calculate something you can use command `print` in the command line, e.g.:&#x20;

```
print 10^4*(3 - sqrt(pi*e))
```

## Working with images:

* To zoom-in to a certain area: \
  select it by drawing a rectangle with left mouse button, then right-click in this area and press "Expand". You can also use "Horiz Expand" ("Vert Expand"), then it will keep vertical (horizontal) scale without change.
* To select a different colormap: \
  right-click on the image -> modify image. \
  Recommended map is grays, however for posters and presentations with white background it is better to tick "Reverse colors". Other options to try are Mocha (reversed), CyanMagenta, Green, Mud, Terrain, etc. Play with it, but please use something with monotonous change in colors.
* To change image dynamic range: \
  Top menu -> ImageProcs -> Image Range... \
  Useful e.g. to highlight some weak features
* To take a line profile: \
  Top menu -> ImageProcs -> Image Line Profiles... \
  Select proper width, direction (Horizontal or Vertical) and position (one can drag blue line in the image by mouse to put it in the right place or change position value). \
  Press "Checkpoint" to save the profile, it will appear in the Data Browser window on the left as a new 1D wave with "\_Prof1" in the end of the name.
* To change axis labels and style: \
  double click on the axis (cursor should look like a double-sided arrow). E.g. to rotate tick labels go to tab "Label Options" and then change label rotation

## Fitting:

### How to find the Fermi level (Quick fitting):&#x20;

Create a line profile at the area where Fermi level can be seen well (without sharp bands crossing Ef). You can increase the width to get a smoother result. Use Ctrl+I and put cursor on your 1D graph to select the fitting area (only part between the cursors will be fitted). Go to Top menu -> Analysis -> Quick Fit -> Sigmoid (Sigmoid definition in Igor Pro is analogous to a Fermi-Dirac distribution function.) In the command line panel (Ctrl+J) you will see all the fitting parameters printed out. xhalf value is the position where sigmoid curve takes it half-maximum value, i.e. chemical potential at the given temperature (close to the Fermi level).

### Multi-peak fitting:&#x20;

Click in the window with 1D graph that you would like to fit to bring it in focus. \
Go to Top Menu -> Analysis -> Packages -> Multi-peak fitting Tick "From Target" to automatically select waves from the target graph. \
Press "Start Set". \
Then "Add or Edit peaks" to add peaks manually. You can select Gauss for peak type and draw peaks by mouse starting by clicking approximately at the apex of each peak. \
After all peaks are added (not necessarily very precise) press "Done" and then "Do Fit". \
You can see all the fitting parameters for each peak by pressing plus symbol next to the peak name.

## Misc

If the Igor file with data analysis (so-called "experiment") was made on a large screen, then on a smaller screen some of the panels will be out of reach. You can bring them back by Top menu -> Windows -> Control -> Retrieve all windows.
