Guide To Learn
Let’s set some simple objectives for our data analysis exercise. This should be challenging enough to require data decomposition and communication in parallel mode, but simple enough to not get bogged down in the details of math or statistics. To that end, I’d like to know To find the answers, we’ll need our program to […]
The complete source code for the weather buoy exercise is available on GitHub at https://github.com/modern-fortran/weather-buoys. If you use git, clone it directly from the command line: Otherwise, you can download it as a zip file from http://mng.bz/aRVo. The CSV data files are located in the weather-buoys/data directory. I encourage you to explore the data files from your […]
The dataset that we’ll use in this exercise consists of hourly measurements of several weather, ocean, and wave parameters, recorded by buoys managed by the NOAA National Data Buoy Center (NDBC). One such buoy is shown in figure 7.2. Figure 7.2 A weather and wave buoy operated by the NDBC. Instruments that measure wind, temperature, […]
For a gentle entry into parallel programming, we’ll process and analyze a real-world weather buoy dataset. This is a miniature example of the big data challenge: how to process a large amount of data that may be too big to fit into memory, or may take too long to process sequentially. The crux of the […]
The way the processor industry is going, is to add more and more cores, but nobody knows how to program those things. I mean, two, yeah; four, not really; eight, forget it. –Steve Jobs (2008) You may be asking, Why write parallel programs? It seems like an unnecessary complication. In general, you’ll want to write […]
Let’s redirect output to standard output and error channels into their respective files from within the Fortran program. Why would you want to do this? For some applications that run for a long time, such as large weather and ocean prediction models that can run for days, it’s useful to write standard output and error […]
This section contains the solution to the exercise in this chapter. Skip ahead if you haven’t worked through the exercises yet.
In our quick-note app, we haven’t had an explicit need to close the file because we’re prompting the user for input and writing to the file in an infinite loop. The only way for the program to quit is by the user pressing Ctrl+C. However, if any of the I/O statements encounters an error (such […]
With the upgrade to the open statement that allows our program to open an existing file in the append mode, we can now continue writing notes to an old file. This is a useful feature, but it assumes that the user would want to continue writing. There are situations where I’d want to start writing from the […]