Writing Conditional Statements in QGIS raster calculator

How to do raster calculation in QGIS?

To add a raster to the raster calculator expression field, double click its name in the Fields list. You can then use the operators to construct calculation expressions, or you can just type them into the box. In the Result layer section, you will need to define an output layer.

How to set NoData value in QGIS?

The other useful step is right-click/export. in this step, you can set pixel values to nodata (Tick the nodata option: add a nodata category: leave ‘from’ blank, and set ‘to’ to 0). this does work with values like -3.40282e+38.

How to calculate raster area in QGIS?

The function get_raster_area is used to calculate the total area of the raster. This is achieved by getting the total area of each cell and then multiply by the number of cells in the coverage raster. The function get_area calculates the total area of each color range by using the NumPy.
 

How do I change raster values in QGIS?

Editing DEM pixels values in QGIS using Serval Plugin

1. Probe button allows you to check the cell values in the raster.
2. Drawing button activate the ability to modify the values of a raster cell.
3. Clicking on the Set raster cell values to NoData button and then in the raster file will set the clicked raster cells to NoData.

How do you calculate raster stats?

Raster item statistics

1. Use the Build Pyramids And Statistics tool, check the Calculate Statistics option, then uncheck the Include Source Datasets option.
2. Use the Synchronize Mosaic Dataset tool and check the Calculate Statistics option to calculate the statistics for each raster item.

How do you use a raster Calculator?

To access the Raster Calculator, select it from the Spatial Analyst toolbar menu. In the dialog box, you can enter Map Algebra in the expression box. The available rasters will be displayed in the Layers list.
 

How to fill NoData in raster?

With a bit of trial and error, we’ve found the most effective way to fill in NoData cells is using the Close Gaps tool. You can find the Close Gaps tool in the Grid toolbox. Change the input raster to your DEM or any raster data set with holes. Click the Okay button and you’re done.
 

What is NoData value in raster?

A nodata value simply is a pixel value in a vector or raster map representing no information. It is not to be confused with a pixel value of 0 (zero).
 

What does != Mean in QGIS?

is not equal to

You can’t “equal” NULL! The operator != does not mean “is not”; it means “is not equal to“.

How do you calculate in QGIS?

Make the layer editable, then use the field calculator ( Layer > Open attribute table > Field Calculator / Ctrl + I or right mouse click shapefile > Open attribute table > Field Calculator/ Ctrl + I ). There is an operator $area that will calculate the area of each row in the table.
 

How does QGIS calculate pixel size?

Right-Click on the Raster image and go to the Metadata tab. Then scroll down to properties and scroll within that text box until you see pixel size.
 

How do you calculate geometry in QGIS?

Calculate Feature Geometry

1. Open Field Calculator. Open the field calculator by clicking the icon on the attribute table toolbar.
2. Define Name and Data Type for a New Field.
3. Enter an Expression to Calculate Geometry.
4. Run the Expression.
5. Turn off Editing Mode.