US Population Pyramid 1850-2000

A population pyramid is a graphical illustration that shows the distribution of various age groups in a population.
When the population is growing, it has the shape of a pyramid.
Below, an animated illustration of how the US population pyramid has changed in the period 1890-2000.
The right-hand side shows the female population, the left side the male population.    

Data Scientists Skills

I have analysed a dataset of 974 LinkedIn job advertisements for data scientists, based in the US. The skills listed in the dataset are classified as "cloud_software_required","database_software_required", "statistic_software_required", and "programming_language_required".
 The most frequent skills in the dataset are the following:


The numbers represent the occurrences of each skill in the dataset. However, this does not tell anything about the associations between these skills, so I have used the a priori algorithm to find the association rules, using a minimum confidence of 70%:
This means, for instance, that in at least 70% of the job descriptions, whenever R was required, Python was required too. Data source: http://www.crowdflower.com/data-for-everyone

Fossil fuels

Below, the percentage of fossil fuels of total primary energy supply (data relative to 2012, source: world bank)

City Prosperity Index

Hover on a city to show a tooltip.
By double-clicking you can zoom in.

The data are for 2012.

Forest Cover

Global mean temperatures: signal and noise

From the point of view of time-series analysis, there are several models for the global mean temperatures: ARIMA models, random walks with drift, etc.

The goal of this post is simply to illustrate interactively the time series X, and its decomposition X=T+S+R, where T is the trend, S the seasonal component, R the remainder. Loosely speaking, R is the 'noise': a stochastic process with mean 0. The decomposition was obtained by LOESS smoothing.

Migration Map

Click on a country to see where its foreign population comes from:
Click on a country to see where its population migrates to:
Data from the World Bank