Lesson 2: Preparation

Transcription

1 Lesson 2: Preparation Using the EartH2Observe data portal to analyse drought indicators 1 Preface This is a step by step tutorial that will help you install all the software required for the further lessons in the ecourse Using the EartH2Observe data portal to analyse drought indicators. It is important that all software is installed and ready to use prior to continuing with this course, in order to be able to fully undertake all the steps in the course. This step by step guide in making the necessary preparations is specifically written for Windows operating systems. For Lesson 4 it is required to work with python scripts. The version of Python we will use in this session is the Anaconda distribution, which includes the most essential python packages, allows for easy installation of new packages and is thus used throughout the session. The prerequisites for taking part in the special session are that users have the following (installed): A google account Anaconda Navigator Python packages: NetCDF4 mpl_toolkits.basemap In this guide we provide a detailed, step by step procedure to establish a google account and install the required version of Python. Table of Contents 1 Preface 1 2 Setting up a Google Account 2 3 Anaconda Navigator Download and Install Anaconda Navigator Test Correct Installation of Anaconda Navigator Add the Python Path in the Environment Variables Test the Environment Variables Path 11 4 Python Packages Install netcdf Install mpl_toolkits.basemap Test Correct Installation of the Python Packages 14 1

2 2 Setting up a Google Account For the first part of the session, you will need to have a google account. If you already have a Google account you can skip this step. If you do not already have one, open an internet browser, such as Google Chrome, Mozilla Firefox, Internet Explorer or Safari. Go to accounts.google.com/signup and fill in all the fields on the righthand side. 2

3 3 Anaconda Navigator 3.1 Download and Install Anaconda Navigator For the second part of the workshop, we will work with existing python scripts. In order to do so, you will need Anaconda Navigator as well as two additional packages installed and working on your computer. NOTE: Step 1: Step 2: Please ensure that there are no existing versions of python on your computer, as this will result in conflicts during the installation and the workshop. Open an internet browser and go to Download the version Python 2.7, for Windows, MacOS or Linux, depending on your operating system. Choose the 64 Bit or 32 Bit version according to your own computer. This does not affect the rest of this tutorial. 3

4 Step 3: Open the installer and click next. Step 4: Accept the Licence Agreement, click I agree. 4

5 Step 5: Select the type of installation (one or all users) and click next. Step 6: Select the destination folder using Browse (such as the Programe_Files folder as is used in this tutorial) and click next. 5

6 NOTE: Make sure there are no spaces in the folder path, python will give a warning otherwise. Also ensure there is enough available disk space (1.8 GB). Step 7: For the Advanced Installation Options, just select the default one Register Anaconda as my default Python 2.7 and click Install. This may take a while. NOTE: We assume you do not have admin access on your computer. If you do have admin access, you can also check the box for Add Anaconda to my PATH environment variable. If you do not check this box, we will add the path after the installation, in Section 3.3 Add the Python Path in the Environment Variables. 6

7 Step 8: Once the installation is complete, click Next and Finish. 7

8 3.2 Test Correct Installation of Anaconda Navigator Step 9: Now that Anaconda Navigator is installed, we will check if it is working using the Anaconda Prompt. Go to start, then type Anaconda Prompt and press enter. Step 10: Type python version and press enter. You will now see the version of Python and Anaconda that are installed on your computer like here below. 3.3 Add the Python Path in the Environment Variables So far we have only used Anaconda Prompt to see if python was working. Now we will manually add the paths for both Anaconda and Python, so we can use it in the command prompt as well. NOTE: This part is only necessary if you did not select the Add Anaconda to my PATH environment variable in Step 7. Step 11: Type in your Anaconda Prompt where conda and press enter. This will show you the folder path of where anaconda is installed. In this tutorial, the path is: C:\Program_Files\Anaconda2\Scripts Type in your Anaconda Prompt where python and press enter. In this tutorial, the path to python is: C:\Program_Files\Anaconda2 8

9 Step 12: Now you will add your paths to anaconda and python manually. Go to your computer (in Windows 10 it is called This PC) and right click, go to Properties Step 13: Go to Advanced System Settings 9

10 Step 14: Go to Environment Variables Step 15: At the section System Variables go to New 10

11 Step 16: At the field Variable name, type PATH At the field Variable value, type the path to the conda.exe file;path to the python.exe file In this example it is: C:\Program_Files\Anaconda2\Scripts;C:\Program_Files\Anaconda2 Step 17: Click OK at all fields that are still open (New System Variable, Environment Variables, and System Properties) to verify all changes. 3.4 Test the Environment Variables Path Now that the paths to Anaconda and Python are manually added, we will check if the computer can indeed find the paths using the command prompt. Step 18: Open a Command Prompt: Go to Start Type cmd.exe Press enter or click on the Command Prompt to open it Step 19: Type python version and press enter As you can see, the version for python is now shown from the command prompt as well. The computer can thus find the paths to Anaconda and Python correctly. 11

12 4 Python Packages Now that you successfully installed Anaconda Navigator and Python 2.7, we will install two packages that will be used in the workshop as well. These packages are netcdf4 and mpl_toolkits.basemap. You will see that this is relatively easy due to the successful instalment of Anaconda Navigator. 4.1 Install netcdf4 Step 20: Open a command prompt. Go to Start and type cmd.exe, and press enter or click on the Command Prompt to open it. Step 21: Type conda install netcdf4 Step 22: It will ask you to proceed, type y and press enter 4.2 Install mpl_toolkits.basemap Step 23: First download the geos package by typing: conda install geos Again, it will ask you to proceed, type y and press enter. 12

13 Step 24: Now install pip, by typing: conda install pip Step 25: Go to the following website: And download the file basemap cp27 cp27m win_amd64.whl Step 26: Depending on the settings of your web browser, the file basemap cp27 cp27mwin_amd64.whl may be downloaded to a specific download directory. In this case, you can either keep the file in the downloads directory, or move the file to the directory where the Python packages are installed, in this tutorial this would be: C:\Program_Files\Anaconda2\pkgs NOTE: The directory of where the basemap cp27 cp27m win_amd64.whl file is located is required for step 29. Step 27: Change the directory in the command prompt to the same folder, type: cd C:\Your_path\Anaconda2\pkgs In this tutorial, the path is C:\Program_Files, so it would be: cd C:\Program_Files\Anaconda2\pkgs Step 28: Install pyproj. In order to do so, type in the command prompt: conda install pyproj Again it asks to proceed, type y and press enter 13

14 Step 29: Install mpl_toolkits.basemap by typing in the command prompt: pip install basemap cp27 cp27m win_amd64.whl Note that depending on the settings of your web browser, the file basemap cp27 cp27mwin_amd64.whl may be downloaded to a specific download directory. In this case you can either move the file to the directory you are working in, or add the full path name to the above comment. If for example the download directory is d:\downloads then the above command should be: pip install d:\downloads\basemap cp27 cp27m win_amd64.whl You will receive the message that you have successfully installed the mpl_toolkits.basemap package. Step 30: Close the command prompt, so all changes are saved. 4.3 Test Correct Installation of the Python Packages Step 31: Open a new command prompt (again, click on start, type cmd, press enter) Step 32: Type spyder and press enter. Now Spyder, which is automatically installed with Anaconda Navigator, will be automatically opened. 14

15 Step 33: Ignore the installation of any updates Step 34: Test if the netcdf4 package is working, type in the IPython console (at the bottom right) : import netcdf4 as nc and press enter 15

16 Step 35: Test if the mpl_toolkits.basemap package is working, type: from mpl_toolkits.basemap import Basemap and press enter If there are no error messages, you have successfully installed Anaconda, Python 2.7, and the packages netcdf4 and mpl_toolkits.basemap. Note that in some cases difficulties may be experienced with the installation of Basemap. If this is the case, please try and use forums on internet to find solutions, as there are several forums available. If it proves impossible then the use of Basemap can be avoided, though the maps developed in the tutorial may not be as elegant as with Basemap. 16