Analysis settings are additional parameters that affect the results of analysis and how the analysis is run. Analysis settings in Map Viewer consist of environment settings and crediting settings.
Analysis settings can be updated for the web map and an individual tool or raster function.
Note:
Analysis settings are not available for tools in ModelBuilder. Map level analysis settings are not applied when the model is run.
Update the analysis settings
When you set analysis environment settings in the web map, any new tool or function that is opened will inherit the relevant settings. Only certain environment parameters will be used by a given tool or raster function. To determine the environments that a tool or function will use, consult the Environments section of the tool's reference page.
Complete the following steps to update the analysis settings for a web map:
- On the Settings (light) toolbar, click Analysis
.
- In the Analysis pane, click Analysis settings.
The analysis settings are categorized into General environments, Raster environments (available with the Imagery Analysis privilege), and Crediting.
- Update the settings as necessary.
- Click Save.
The analysis settings are updated. To return to the original settings, click Reset defaults.
Update the environment settings for a tool or function
You can set environments individually for any tool or function that you open in the tool or raster function pane, under the Environment settings parameter group. The environments set for a tool or function will override the same setting for the web map. These settings will only be used until the tool or function is closed and will not be saved if it is opened again. If you reopen a tool or function from History, it will repopulate with the environments that were used when it was previously run.
Environment settings
Environment settings ensure that aspects of the analysis, such as the output coordinate system and processing extent, are controlled for your analysis runs.
Output coordinate system
Output coordinate system specifies the coordinate system for analysis and the result layer.
Projected coordinate systems preserve some aspects of features (area, shape, distance, or direction) while distorting other aspects. It is important to choose an output coordinate system that will minimize distortion in the most important aspects of your analysis. For example, an equal distance projection will minimize distance distortion when using Summarize Nearby.
The following options are available for the Output coordinate system setting:
- Same as input (default)—The result of your analysis will be in the same coordinate system as the input.
- Choose coordinate system—The result of your analysis will be in the coordinate system you choose. Click the Browse coordinate systems button to choose from a list of coordinate systems.
- Same as layer—The result of your analysis will be in the same coordinate system as an existing layer on the web map. Click the Layer button to choose from a list of layers.
Note:
If Same as layer is specified and the chosen layer has a coordinate system defined by a Well-Known Text (WKT) string, the coordinate system will not populate in the parameter if a tool is reopened from the History pane. You can reset Output coordinate system before running the tool.
Most web maps use Web Mercator as the default projection. The Web Mercator projection distorts distance and area calculations and is not recommended for most analysis. Try the Make a web map without Web Mercator tutorial to learn how to change the projection of a web map.
Geographic transformations
Geographic transformations specify transformation methods that can be used to project data. For tools that honor the Geographic transformations environment, you an specify a list of transformation methods from system-supplied transformations. Only the transformations appropriate to the project will be used and all the others will be ignored.
This environment currently only supports raster analysis.
Processing extent
Processing extent specifies the extent or boundary when the analysis is run. All input features or cells that are completely within or that intersect the specified extent are used in the analysis. The processing extent can be used to limit the analysis to a specific area.
Tip:
If you are analyzing large datasets, you may want to update the processing extent in the analysis settings for the web map. That way, the extent will be used for all tool runs.
The following options are available:
- Full extent (default)—The extent provided by the tool or raster function.
- Coordinates—The extent is defined by the coordinates you provide to create a bounding rectangle. Click the Set coordinates from current display extent button to populate the coordinates based on the visible extent.
- Display extent—The extent is defined by the visible extent at the time when the Run button is clicked.
- Layer—The extent is defined by the spatial extent of an existing layer. Click the Layer button to choose from a list of layers.
Snap raster
Snap raster adjusts the extent of the output raster layer so it matches the cell alignment of the specified Snap raster layer for raster analysis. Click the Layer button to choose from a list of layers.
Cell size
Cell size specifies the cell size or resolution that is used to create the output raster layer in raster analysis. The following options are available:
- Maximum of inputs (default)—The cell size is defined by the largest cell size of all input layers.
- Minimum of inputs—The cell size is defined by the smallest cell size of all input layers.
- As specified—The cell size is defined using a custom number value.
- From layer—The cell size is defined by the cell size of an existing layer. Click the Layer button to choose from a list of layers.
Mask
Mask specifies a raster layer or feature layer that is used to define your area of interest for raster analysis. Only those cells that fall within the analysis mask are considered in the analysis operation. Click the Layer button to choose from a list of layers.
If the analysis mask is a raster, all cells that have a value will define the mask. Cells in a mask raster that are NoData are considered to be outside the mask and will be NoData in the analysis result layer.
If the analysis mask is a feature layer, it will be internally converted to a raster when the analysis is run. For this reason, ensure that Cell size and Snap raster are set appropriately for your analysis.
Resampling method
Resampling method specifies how to interpolate pixel values when transforming your raster dataset. This environment is used for raster analysis when the input and output do not line up, when the pixel size changes, when the data is shifted, or a combination of these situations. The following options are available:
- Nearest neighbor—Used primarily for discrete data, such as a land-use classification, since it does not create new pixel values. This method is also appropriate for continuous data when you want to preserve the original reflectance values in imagery for accurate multispectral analysis. It is the most efficient in terms of processing time but may introduce small positional errors in the output image. The output image may be offset by up to half a pixel, which may cause the image to have discontinuities and a jagged appearance.
- Bilinear interpolation—This method is most appropriate for continuous data. It performs a bilinear interpolation and determines the new value of a cell based on a weighted distance average of the four nearest input cell centers. It creates an output image that is smoother in appearance than Nearest neighborhood but alters the reflectance values, which results in blurring or loss of image resolution.
- Cubic convolution—Suitable for continuous data. This method performs a cubic convolution and determines the new value of a cell based on fitting a smooth curve through the 16 nearest input cell centers. The result is geometrically less distorted than the raster achieved with Nearest neighbor and sharper than Bilinear interpolation. In some cases, it can result in output pixel values outside the range of input cell values. If this is unacceptable, use the Bilinear interpolation method instead. Cubic convolution is computationally intensive and takes longer to process.
Crediting
Note:
The crediting analysis settings are available in the Analysis settings pane for the web map and cannot be updated for individual tools or raster functions. All analysis runs will honor the crediting settings.
Apply credit threshold determines whether a warning message will appear if the estimated number of credits surpasses the specified threshold (enabled) or if the analysis will run without displaying a message regardless of the estimated credit consumption (not enabled).
Credit threshold determines the number of credits that can be consumed in a single analysis run without prompting a warning message. If the estimated number of credits surpasses the threshold, the warning message appears with the options to cancel the analysis or proceed with the analysis run. The default credit threshold is 100. Credit threshold is available if Apply credit threshold is enabled.
Tip:
You can reduce the size of a dataset and the number of credits consumed when the tool is run by applying a filter or updating the Processing extent setting. You should only filter your data or change the processing extent if your analysis does not require the full dataset.
The analysis will still honor credit budgeting settings for the organization.