R FirstSteps - Revision history

Rb at 21:39, 14 January 2015

2015-01-14T21:39:11Z

Rb: /* Working Directory */

2015-01-12T17:11:26Z

‎Working Directory

Rb at 20:38, 10 January 2015

2015-01-10T20:38:11Z

Rb at 20:37, 10 January 2015

2015-01-10T20:37:33Z

Rb: /* Creating Variables */

2015-01-10T20:24:53Z

‎Creating Variables

Rb: /* Creating Variables */

2015-01-10T20:24:38Z

‎Creating Variables

Rb: /* Creating Variables */

2015-01-10T20:24:26Z

‎Creating Variables

Rb: /* Creating Variables */

2015-01-10T20:03:43Z

‎Creating Variables

Rb at 20:03, 10 January 2015

2015-01-10T20:03:26Z

Rb at 20:01, 10 January 2015

2015-01-10T20:01:57Z

← Older revision		Revision as of 21:39, 14 January 2015
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	But let's stop this silliness and proceed to some more useful activities.		But let's stop this silliness and proceed to some more useful activities.

		+	== Scripts ==
		+
		+	When working with R you will typically want to perform a number of steps to perform your analysis. Perhaps you will first have to import data, then do some data transformation, run a regression, plot some regression residuals and save this plot so that you can include it into a written report.
		+	While in menu-driven software packages you would perform these steps by step after step using the menus of the software, the workflow in R will be somewhat different.
		+
		+	You will first provide R with a set of written instructions to achieve all the above steps. Once they are collectively written down in a file, here called a script file, you click one button and upon that click R will execute all these tasks in one fine swoop. One great aspect of this way of working is that you save this script file and it is a record of everything you did to obtain your results. This is an excellent way to communicate your work to colleagues. Even better, you can go back, make a small change in your instructions and then easily replicate your entire analysis.
		+
		+	We will see an example of such a script as we introduce packages just below.
	Return to the R [[R\|Start page ]].		Return to the R [[R\|Start page ]].

@@ Line 11: / Line 11: @@
       setwd("T:/ECLR/R/FirstSteps")
-It will be best to enter this command into the script file which you created above (and which is empty so far. You should also save this script file (e.g. "Firssteps.R"). Once you saved the script file find the little button called "Source" on the top right corner of the Script file window. Press this or alternatively press "CTRL+SHIFT+s" and R will execute all commands in your script file (right now this is only one, setting the working directory).
+It will be best to enter this command into the script file which you created above (and which is empty so far. You should also save this script file (e.g. "Firssteps.R"). Once you saved the script file find the little button called "Source" on the top right corner of the Script file window ([[File:R_sourcebutton.JPG|frameless|500px]]). Press this or alternatively press "CTRL+SHIFT+s" and R will execute all commands in your script file (right now this is only one, setting the working directory).
 == Creating Variables ==

← Older revision		Revision as of 20:38, 10 January 2015
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	Open your RStudio software and you should see 3 windows titles "Console" (most likely on your left), a window with two tabs ("Environment" and "History") and a third window that has 5 tabs ("Files", "Plots", "Packages", "Help" and "Viewer"). Before we look at these in detail I want you to open a fresh script file. On the menu choose FILE - NEW FILE - R SCRIPT. You should then see a fourth window. We shall soon get back to this.		Open your RStudio software and you should see 3 windows titles "Console" (most likely on your left), a window with two tabs ("Environment" and "History") and a third window that has 5 tabs ("Files", "Plots", "Packages", "Help" and "Viewer"). Before we look at these in detail I want you to open a fresh script file. On the menu choose FILE - NEW FILE - R SCRIPT. You should then see a fourth window. We shall soon get back to this.
−
−	~~== Upload a data file to your working directory ==~~
−
−	In the first instance I want you to download this [[media:mroz.xls\|mroz.xls]] Excel file that contains a dataset which we will use for our first steps in R. It is a well used cross-sectional dataset with 753 observations of female members of the labour force in the US (in 1975). It contains variables such as the number of children, the wage, the hours worked etc. A bit more detail on the data and the variables can be found in this [[media:mroz_description.pdf\|file]]. See also [https://ideas.repec.org/p/boc/bocins/mroz.html].
−
−	Make sure that you note down in which folder you save this file. Save it in a folder in which you want to save your work. We shall soon call this folder our working directory. At this stage we have not yet made the data available to R. This will come soon!

	[[File:RStudioscreen.jpg\|frameless\|500px]]		[[File:RStudioscreen.jpg\|frameless\|500px]]

← Older revision		Revision as of 20:37, 10 January 2015
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		+	[http://youtu.be/z9rH0RPuPMc?hd=1 Online Demonstration]
		+
	Open your RStudio software and you should see 3 windows titles "Console" (most likely on your left), a window with two tabs ("Environment" and "History") and a third window that has 5 tabs ("Files", "Plots", "Packages", "Help" and "Viewer"). Before we look at these in detail I want you to open a fresh script file. On the menu choose FILE - NEW FILE - R SCRIPT. You should then see a fourth window. We shall soon get back to this.		Open your RStudio software and you should see 3 windows titles "Console" (most likely on your left), a window with two tabs ("Environment" and "History") and a third window that has 5 tabs ("Files", "Plots", "Packages", "Help" and "Viewer"). Before we look at these in detail I want you to open a fresh script file. On the menu choose FILE - NEW FILE - R SCRIPT. You should then see a fourth window. We shall soon get back to this.

← Older revision		Revision as of 20:24, 10 January 2015
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	But let's stop this silliness and proceed to some more useful activities.		But let's stop this silliness and proceed to some more useful activities.

−	Return to the R ~~Start page~~ [[R]].	+	Return to the R [[R\|Start page ]].

← Older revision		Revision as of 20:24, 10 January 2015
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	But let's stop this silliness and proceed to some more useful activities.		But let's stop this silliness and proceed to some more useful activities.
		+
		+	Return to the R Start page [R].

@@ Line 31: / Line 31: @@
 I only used the value 5 so that you can see in the environment tab that the value has now changed to 5. Once you have a variable defined you can use it in the definition of further variables as follows:
-      > test 2 <- test1 + 2.7
+      > test2 <- test1 + 2.7
 But let's stop this silliness and proceed to some more useful activities.

← Older revision		Revision as of 20:03, 10 January 2015
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	> test1 <- 5		> test1 <- 5

−	I only used the value 5 so that you can see in the environment tab that the value has now changed to 5.	+	I only used the value 5 so that you can see in the environment tab that the value has now changed to 5. Once you have a variable defined you can use it in the definition of further variables as follows:
		+
		+	> test 2 <- test1 + 2.7
		+
		+	But let's stop this silliness and proceed to some more useful activities.

← Older revision		Revision as of 20:01, 10 January 2015
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	> test1 = 4		> test1 = 4

−	Once you hit ENTER you will find an entry in the "Environment" tab on the right hand side. This tells you that you have just now created a variable, named test1, that has the value 4. If you have done any form of programming, then this sort of command should look very familiar. However, this isn	+	Once you hit ENTER you will find an entry in the "Environment" tab on the right hand side. This tells you that you have just now created a variable, named test1, that has the value 4. If you have done any form of programming, then this sort of command should look very familiar. However, this isn't the way how "things are done" in R. What you should really do to achieve the same is to use the following assignment command:
		+
		+	> test1 <- 5
		+
		+	I only used the value 5 so that you can see in the environment tab that the value has now changed to 5.