📄
Data Transformation and Visualization
  • Introduction
  • Examples
  • Tables
  • The Document Object Model
  • Canvas
  • Sets and Series
  • Colour
  • Geometry
  • Usage License
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  • Extraction of CSV data
  • Color Swatches and SVG output
  • Constructing SVG from instructions

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Examples

Examples

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Last updated 4 years ago

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There are a number of example applications in the cmd folder which demonstrate features of the code. In order to build the examples, you'll need a working go compiler. There is a makefile in the repository which can be used to compile the examples:

bash% git clone [email protected]:djthorpe/data.git
bash% cd data
bash% make
bash% cd build/cmd && ls

A temporary build folder is created for intermediate and binary data. You can remove the build folder and any other intermediate data using the make clean command.

Extraction of CSV data

The csvreader command can be used to extract CSV data and transform to ASCII, CSV, SQL or XML format:

bash% export URL=https://raw.githubusercontent.com/google/dspl/master/samples/google/canonical/countries.csv
bash% ./build/cmd/csvreader (-xml|-sql|-csv) ${URL}

These screenshots demonstrate ASCII and SQL output:

The command line arguments are as follows:

Syntax:

  csvreader <flags> <url|path> <url|path>...

Usage of csvreader:
  -header
        Read and write table header (default true)
  -sql
        SQL output
  -xml
        XML output
  -csv
        CSV output
  -delim string
        CSV field delimiter

Color Swatches and SVG output

The colorswatch command demonstrates:

  • Enumerating a swatch into a palette of colors;

  • Generating an SVG canvas and writing to stdout;

  • Using color distance to set an appropriate foreground colour.

For example, the following command produces a palette of red, blue and green colours:

bash% ./build/cmd/colorswatch red blue green > build/swatch.svg
bash% open build/swatch.svg

Constructing SVG from instructions

The tiger command takes a set of input instructions and generates an SVG file. The instructions come from an example on the Raspberry Pi and are stored in etc/dataset/tiger_data.txt. In order to generate the SVG file, use the following command:

bash% ./build/cmd/tiger -rotate 180 etc/dataset/tiger_data.txt > build/tiger.svg
bash% open build/tiger.svg

The resultant output is as follows:

csvreader ASCII output
csvreader SQL output
Tiger SVG output