ClemRz

Battery pack capacity formula

Use this formula to compute a lithium-ion battery pack capacity:

% = 1.25 * v / s - 3.875

Where % is the remaining capacity as a fraction of 1 (multiply by 100 to get a percentage), v is the pack voltage and s is the number of cells in series.

ClemRz

Resize images and put them into a single pdf

First install ImageMagick

Run the following commands:

mogrify -resize 663x1024 *.jpg
for i in `seq 0 26`; do convert $(printf "filename-%03d" $i).jpg $(printf "filename-%03d" $i).pdf; done  
gs -dBATCH -dNOPAUSE -q -sDEVICE=pdfwrite -sOutputFile=temp.pdf $(for i in `seq 0 26`; do printf "filename-%03d.pdf " $i; done)

ClemRz

Extracts a CSV speed, elevation and distance table from a KML file.

This is a Python script that extracts a table with several columns from a KML file: timestamp, elapsed time, distance, speed, elevation, elev. gain, elev. loss and stop time.

How to use this script

Open a terminal and run:

python3 script.py /path/to/your/file.kml

ClemRz

Trail maps production with QGIS

Table of Content

• I. Setup
• II. Create a map from an existing map
• III. Add layers
  • III.a. DEM
    • III.a.1. Contour Lines
    • III.a.2. Hill Shades

ClemRz

from PyQt4.QtCore import QSettings

class Selection(QgsMapTool):
	def __init__(self, canvas, layer):
		QgsMapTool.__init__(self, canvas)
		self.canvas = canvas
		self.layer = layer

	def getFeatureRequest(self):
		sr = self.searchRadiusMU(self.canvas)

ClemRz

How to print a 1:1 (or any scale) 2D graphic from a Sketchup Make 3D model

1. Export your model to STL file (Install the Sketchup STL extension: https://extensions.sketchup.com/en/content/sketchup-stl)
2. Import the STL file in a new TinkerCAD model: https://www.tinkercad.com
3. Export the TinkerCAD model to 2D SVG graphic
4. Open the SVG file in Inkscape
5. Make sure you page is correctly set up and print to the desired scale

The End

ClemRz

How to add more file fields to the GPS Visualizer convertion tool

1. Go to http://www.gpsvisualizer.com/ and choose a file converter
2. Click the link Show additional file input boxes
3. Open the developper tool's console
4. Copy and paste the script below

Enjoy!

ClemRz

How to download the KML from an AllTrails page without PRO account

1. Open a trail page in your favourite browser, for instance: https://www.alltrails.com/explore/trail/us/arizona/south-kaibab-to-phantom-ranch-to-bright-angel-trail
2. Open the developper console
3. copy and paste the script below (script.js)
4. execute it, you should see a KML file being downloaded

The last file below is for advanced users.

Enjoy!

ClemRz

How to import OSM vectorial data into QGIS

Follow the steps:

1. Go to https://www.openstreetmap.org and log in
2. On the right, open the layer menu and check the public GPS trace
3. On the top-left corner click on "Export"
4. Enter the coordinates
5. Click on Export button
6. Open the file with a text editor

ClemRz

How to add vectorial PALSAR-2 Global Forest data in QGIS

Follow those simple steps:

1. Go to http://www.eorc.jaxa.jp/ALOS/en/palsar_fnf/data/index.htm and select latest FNF map.
2. Select the region and sub-region
3. Download the FNF file
4. In your QGIS project open the file that has no extension
5. If you need to merge several FNF files, save them first as GTIFF (raster) and use the merge tool in the raster menu
6. In the raster menu select Conversion > Polygonize, remember to check the "field name" checkbox