Monthly Archives: March 2016

My Maps & Google Earth

One of the most recent tutorials that was completed in Digital History (hist5702w) was on how to use the Google My Maps and Google Earth applications. These applications both utilize Google’s powerful mapping technology to allow you to do a number of different tasks. My Maps allows you to see a map of the world and add personalized features such as your favourite running routes while Google Earth is designed to allow you to see the globe in a three dimensional fashion and also with special features like satellite imagery and three dimensional buildings.

I found this particular tutorial to be really useful and fun! I will use both of these programs in the coming future for different reasons. For example, I have always wanted a way of keeping track of the accessible restaurants and bars in Ottawa that I like most. My Maps is the perfect program to do just that. It will let me see things like the distance between them, and even possible ways to get to and from them. Google Earth is also going to be helpful down the road but for different reasons. For example it will allow me to see what a place looked like at different points in history and compare it to the present. This is a great feature but one that I will need to look into learning how to use properly.

Below you can find my notes taken during the process of completing this tutorial. Take a look and let me know what you think!

My Maps

Tutorial Notes

- logged into My Maps on Google Maps

How My Maps works:

- You can create a new map to map out anything, from your favourite parks to historic places

- When searching for historic places just be sure that you have the correct name as Google may have different information (for instance Berlin or Constantinople Ontario)

- From the toolbar you can do things like pan the map, drop a pin in it, or draw lines and shapes

- You can also style your map by clicking on the style button on the left side of the menu when you are adding new features to the map.

- You can then share your map online or crowdsource it to get input from others to make your map more powerful

- To import a data set from file just click ‘add layer’ -> ‘import data set’

My First Test Map

- My first map is called ‘Accessible Ottawa’ and it is intended to map out different locations in Ottawa that are wheelchair accessible such as, pubs, restaurants, museums, schools, etc

- Added Sir John A’s pub on Elgin St by searching for it in the search bar

- Then as a sample of importing a data set from file I downloaded the sample CSV file that was provided in the tutorial of different locations around the globe

- It then asks you which column that Google should use from the file to find the locations, in this sample i chose column A) Place

- Then it asks you which column you would like google to use as a title for those locations, in this sample i chose column B) Commodity

- The map contains all the locations where the UK fat imports were located around the world during the 1890s

- My Maps allows you to organize the locations uniformly by clicking ‘style’ -> ‘style by data column’ -> ‘commodities’

- The map then shows all the different locations of each commodity by colour and then living them on the left side menu with the amount of locations that the UK imported that particular commodity at that time

- The program does have many other features including in this instance being able to organize the items by place rather than commodity, but it has limitations such as:

- Only being able to import the first 100 rows of a spreadsheet

- Only allows for three data sets in a map so therefore only three hundred features can be handled

Creating Vector Layers:

- Simply put vector layers are just points, lines or polygons used to mark geographic features

- for example points are often used to mark important locations, lines for railways or roads, and polygons for different areas such as a city ward, or a field

- To add a vector layer click on ‘add layer’ and then rename the layer ‘layer 2′ or whatever you prefer

- NOTE: Beside the title of the layer there is a checkbox, when the checkbox is not checked it will not appear in your map

- Base Map: At the bottom of the menu window, there is a line that says ‘base map’. A base map is a map** depicting background reference information such as roads, borders, landforms, etc. on top of which layers containing different types of spatial information can be placed. Google’s Maps allows you to choose from a variety of base maps, depending on the kind of map you want to create.

- A commonly used base map is satellite imagery but that can often be distracting

- You can choose which base map you would like to use by clicking on the arrow to the left of ‘base map’

- When you click on it a submenu appears that lists options such as:

- satellite

- light political

- light and dark landmass

- simple atlas

- mono city

- whitewater

- To add a point on the map or ‘Marker’ you click on the add marker button under the search menu

- When you do so it will appear under ‘Layer 1′

- To add a Line or Shape to the map you need to click the ‘add line or shape’ icon box directly to the right of the Markers symbol – You can add details about these lines and shapes in the same way that you add details about the Markers

- You then connect the dots of the line to create a formation

- This is useful for outlining farmers fields or city boundaries

- I had a bit of trouble with this but managed to make jagged lines and link them but not any perfectly straight

- you can then share your map online with the ‘Share’ feature which lets you share it through any social media such as Facebook or email

- you can also share it by embedding it in your blog or website

- another option that it gives you is to export the map or individual layers so that you can use it in other programs like Google Maps which I managed to do successfully

Google Earth

- Similar to Google Maps Engine Lite but with additional features

- For example, it provides 3-D maps and access to data from numerous third party sources, including collections of historical maps

- Google Maps also doesn’t require you to install anything on your computer while Google Earth does

- You can choose for the application to display any number of different layers of information including:

- Borders

- Roads

- 3D Buildings

- Ocean

- Weather

- Gallery

- Global Awareness

- and more

- It also has the option of displaying historical maps

- For example the world globe from different years in history

KML (Keynote Markup Language) Files

- this is a file format that was developed by google to save and export data

- it can store many different types of GIS data, including vector data

- it also allows you to import maps from other platforms including Google My Maps

- I successfully downloaded the ‘Map of the St. Lawrence Seaway and Power Project’

- You can also add special features to your map to your map in the same way you could in My Maps such as different lines and styles

- You can even go so far as to record a tour of the map which may be useful for presentations

- Successfully added a few different paths and shapes to the map

- you can even go so far as to search for a specific location in the menu bar on the left and ‘fly’ there

- tutorial asked that i ‘fly’ to lake st clair and draw a border around it

- this was accomplished successfully

- next i successfully added this polygon into the map of the st lawrence seaway project

- then i saved this new version of the map as a kml file by right clicking on the seaway and then choosing ‘save place as or email’

Adding Scanned Historical Maps

- Google Earth gives you the power to add historical maps to the globe

- main purpose for uploading a digital map, from a historical perspective, is to place it over top of a Google Earth image in the browser. This is known as an overlay. Performing an overlay allows for useful comparisons of change over time.

- to accomplish this you begin by clicking on the ‘show historical imagery’ button on the top of the toolbar

- then when you choose the images you plan to use, click on the ‘Add Image Overlay’ icon on the top toolbar

- unfortunately i can’t seem to find this button but maybe somebody out there will be able to help figure that out…

Topic Modelling

This week I had the opportunity to lead the class in a discussion about topic modelling. What is that you ask? Well it is basically a group of computer programs, Mallet being the most common (which we were working with), that take a text and try to extract topics from that text. Now, computers obviously do not understand the meanings of the words that are extracted from the text but they are able to find relationships between them by judging the frequency in which they appear. From these relationships words are then placed into baskets by the computer that are given a topic as a title.

Working with Mallet manually through the command line though is a ver strenuous and meticulous process. For this reason Dr Graham suggested that I use a GUI (Graphical User Interface) program that runs on Mallet. This program is much more user friendly for me as it allows me to navigate and create a topic model by clicking rather than typing in code on the command line. The only downside being that the options were then limited to what the program thought was necessary and not what I may have considered necessary. Whereas if I was working with Mallet directly on the command line I could specify the instructions a bit more for my needs.

When completing this tutorial, I had a few different hiccups along the way. First was making a solidified list of stopwords (list of words for the computer to ignore during its analysis) that would help me find more detailed topics. Thanks to the help of Dr Graham I was guided to a list of stopwords that was published by a historian known as Ted Underwood. This list consisted of over 6,000 words including Roman numerals. Once I began using this list the topics that the computer began making topics that were highly accurate when it came to analyzing my thesis. Another hiccup that I came across was figuring out how to analyze multiple files at one time when using the GUI. This was quickly figured out by being shown that instead of selecting the individual files, I simply select the files that they are all in. So if I was wanting to select multiple article sources from research that I had done for instance I would just put them all in one file then select that file in particular. Finally, I had great trouble figuring out how to visualize these models with Excel. For instance graphs can be made that show how different words relate to one another. This in particular is something that I will have to continue to look at as I have yet to completely grasp it.

Below are the notes that I took during the process of completing this tutorial…

What is Topic Modelling?
– topic modelling tools like Mallet look at patterns in the use of words in an attempt to inject local meaning behind vocabulary
– tools like this are transforming the practice of reading into what Matthew Kirschenbaum calls ‘distant reading’
– What is meant by this is that computers and programs such as Google are making scanning millions of books for themes and patterns at the same time possible
– just because you can use these programs though doesn’t mean you should
– If you are trying to look over only one document for instance tools like Volant Tools, that count frequency of words may get the job done just fine
– topic modelling is all about finding topics in mass amounts of texts
– texts can be anything from a blog post to an email to a book
– Topic modelling programs do not know anything about the meaning of the words in a text.
– Instead, they assume that any piece of text is composed (by an author) by selecting words from possible baskets of words where each basket corresponds to a topic. If that is true, then it becomes possible to mathematically
– decompose a text into the probable baskets from whence the words first came.
– The tool goes through this process over and over again until it settles on the most likely distribution of words into baskets, which we call topics.
– Topic Modelling is often referred to synonymously as LDA

Tutorial
– when working on Mallet in the Terminal always remember to add ./ before entering a command
– There are 9 mallet commands that we can learn and sometimes we can even combine these instructions
– after attempting to work with while I am trying to use a different program that is essentially the same concept, however it is a GUI. Unlike Terminal I will not have to meticulously enter each command manually but rather have a much less tiring way of completing the tutorial by clicking on different options
– seeing as I don’t have the sample .txt files provided by Mallet I will use some of the sources from my thesis to complete the tutorial
– First I imported the files that I wanted to analyze
– next i made sure that there was stop words in place (it had already automatically set itself up to remove the default Mallet stop words such as, and, the, of, but, if, etc)
– however i wanted to make sure that the stop words were more comprehensive so that it would find more meaningful themes in the file
– so i googled stop word dictionary and it lead me to http://www.ranks.nl/stopwords (Dr Graham suggested that i use ted underwood’s list of stopwords that contains over 6000 words including roman numerals found here: https://www.ideals.illinois.edu/bitstream/handle/2142/45709/stoplist_final.txt?sequence=2)
– I filled out all the stop words that it had under a new text file in text wrangler but cannot figure out how to activate it instead of the default Mallet stop words as whenever I try to open a stop word file it does not let me open any files inside of the user hollispeirce
– makes me think that perhaps i could solve this problem by saving it outside of these files…
– only file i am able to get into is the dropbox folder
– managed to save it in dropbox but when i went to open it it did not appear so I will continue on with simply using the default mallet list
– the first time i attempted to have it learn 200 topics i asked it to learn 200 topics iterations and print 10 topic with a 0.05 proportion threshold. with 200 different topics
– it spat out 200 lines of random words, majority of which did not relate to the overall theme of the thesis paper but included things like “gz, uv, ku, rr, autumn,” etc
– HOWEVER when i reduced the number of iterations dramatically to a much more reasonable list that is much more accurate and includes words such as “incunabula, book, digital, information, ebook, scroll, history, disabled” but does include a few two letter words like the other so i will try reducing the number of iterations again
– that didn’t appear to do anything
– I attempted to import all the files of my thesis into one importation but could not not figure out how to open it with text wrangler after converting it from a .docx file to a .txt file even though it opened just fine in text editor (i will try opening the .docx file in text wrangler and see if that solves the issue)
– solved this issue by being shown by dr graham that i only highlight the file that the .txt files that are needing to be analyzed are in
– only problem with that was that the file not only contained my thesis .txt files but also contained the settings for Notational Velocity which, as he explained was why i was getting a bunch of random two letter words in my list of topics
– to solve this problem all i need to do is create a new file that only has my thesis inside of it
– so i then did this but it did not create a list of topic words in the topic modelling like it normally did but instead it just repeated where the topics were saved
– when i looked the file up though it had worked as suspected and excluded all the two letter words so now i just need to narrow the topics to be even more specific
– having trouble making a chart with topic model from my thesis so i am going to try using the jesuit relations files