data-analysis

Combine PDF Files using Automator

Kazu Nozue / 2022-02-04
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A PDF file is especially useful when multiple PDF files can be combined into one file. When you combine a couple of PDF files, it is easy to use Preview in Mac (sorry I do not know Windows computers). However, if you want to combine hundreads of files, using Preview is not good choice. Fortunately…
data analysis

En-ROADS, a climate simulator

Kazu Nozue / 2021-12-15
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2021 Nobel prizes for physics were awarded to Syukuro Manabe and Klaus Hasselmann for understandig complex systems, and Giorgio Parisi for the physical modelling of Earth’s climate. Those areas are very important to understand global warming. After there initial works, we have an web-based…
data analysis

Useful R techniques 3: row-wise and col-wise sum

Kazu Nozue / 2021-11-04
df <- tibble(x = 1:2, y = 3:4, z = 5:6) df2 <- rbind(df, colSums(df));df2 # col-wise ## # A tibble: 3 × 3 ## x y z ## <dbl> <dbl> <dbl> ## 1 1 3 5 ## 2 2 4 6 ## 3 3 7 11 df3 <- cbind(df,rowSums(df));df3 # row-wise ## x y z rowSums(df) ## 1 1 3 5 9 ## 2 2 4 6 12 Row-wise…
data analysis

Backup iphone to an external harddrive

Kazu Nozue / 2021-04-07
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If your computer free space is not enough for backing up your iphone, you can use an external harddrive. You can find an instruction. […] directory name […] command line […] directory name […] iTunes
data analysis

The second solar system project: timeline

Kazu Nozue / 2021-04-04
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Increasing self-production of electricity at home has a couple of benefits. […] My first solar system produced 3803 kWh per year (an average of 2015 - 2020) 1. Switching a gas-powered car to an electric car in 2019 increased electricity comsumption 2.5 times (from (3938 to 10342 kWh). The…
data analysis

Useful R techniques 2

Kazu Nozue / 2021-03-19
Key words are key, value, inner_join(), left_join(), right_join(), full_join, semi_join(), and anti_join(). Read a book written by Hadley Wickham and Garrett Grolemund.