.QLF File

What is a QLF file?

A QLF file is a Quick Load File used by the SWI-Prolog programming language. It is a precompiled format of a Prolog source file that loads much faster than the source file itself. QLF files are also typically more compact than source files.

QLF files can also be used to transfer spatial data between different software applications. The Centre for Topographic Information Sherbrooke (CITS) Data Transfer Format is a published ASCII format that uses the .QLF file extension. This format is used by many different geospatial software packages, including FME, ArcGIS, and QGIS.

To open a QLF file, you can use the consult/1 predicate in SWI-Prolog. You can also use the CITS Data Transfer Format Reader/Writer in FME to read and write QLF files.

Here are some of the benefits of using QLF files:

• Faster load times than source files
• More compact than source files
• Can be used to transfer spatial data between different software applications

QLF files are a useful tool for Prolog programmers and geospatial professionals. They can help to improve performance and make it easier to share data between different software applications.

How to open a QLF file?

There are two main ways to open a QLF file:

1. Using SWI-Prolog: To open a QLF file in SWI-Prolog, you can use the consult/1 predicate. This predicate takes the path to the QLF file as its argument and loads the file into the Prolog interpreter.

:- consult('my_file.qlf').

2. Using FME: FME is a data integration platform that can be used to read, write, and convert QLF files. To open a QLF file in FME, you can use the CITS Data Transfer Format Reader/Writer.

How to convert a QLF file to another file format?

To convert a QLF file to another file format, you can use FME. FME supports a wide range of geospatial formats, including Shapefile, GeoJSON, and KML.

To convert a QLF file to a Shapefile using FME, follow these steps:

1. Open FME and create a new workspace.
2. Add the CITS Data Transfer Format Reader to the workspace.
3. Connect the CITS Data Transfer Format Reader to the Shapefile Writer.
4. Set the input and output file paths.
5. Run the workspace.

What is a QLF file used for?

QLF files are used for a variety of purposes, including:

• Loading Prolog source files
• Transferring spatial data between different software applications
• Storing spatial data in a compact format

How do I read a QLF file in FME?

To read a QLF file in FME, you can use the CITS Data Transfer Format Reader. This reader extracts features from a QLF file one at a time and passes them on to the rest of the FME for further processing.

To read a QLF file in FME, follow these steps:

1. Open FME and create a new workspace.
2. Add the CITS Data Transfer Format Reader to the workspace.
3. Set the input file path.
4. Connect the CITS Data Transfer Format Reader to a transformer or writer.
5. Run the workspace.

How do I create a QLF file from a CSV file?

To create a QLF file from a CSV file, you can use FME, follow these steps:

1. Open FME and create a new workspace.
2. Add the CSV Reader to the workspace.
3. Connect the CSV Reader to the CITS Data Transfer Format Writer.
4. Set the input and output file paths.
5. Define the QLF file schema.
6. Run the workspace.

How do I convert a QLF file to a Shapefile?

To convert a QLF file to a Shapefile, you can use FME, follow these steps:

1. Open FME and create a new workspace.
2. Add the CITS Data Transfer Format Reader to the workspace.
3. Connect the CITS Data Transfer Format Reader to the Shapefile Writer.
4. Set the input and output file paths.
5. Run the workspace.

How do I import a QLF file into Google Earth?

To import a QLF file into Google Earth, you can use the Google Earth KML Converter. This tool converts KML files to Google Earth KMZ files.

To import a QLF file into Google Earth using the Google Earth KML Converter, follow these steps:

1. Download the Google Earth KML Converter.
2. Run the Google Earth KML Converter and select the QLF file that you want to import.
3. Click the "Convert" button.
4. Open the converted KMZ file in Google Earth.