Geographical Plotting with Python Part 1 - Your first Geo Chart!

Key Takeaways

hello everybody and welcome to the geographical plotting within Python tutorial or basically how to plot data onto a map using uh latitude and longitude to do this we're going to be using a module called base map which works alongside map plot livs so a lot of your map plot lib skills will be directly transferable here I'm going to assume that anybody watching this already has matplot lib and pil if you don't you should definitely get matplot lib and probably uh go back a little bit and watch some of the matplot lib tutorials since they're going to cover some stuff that I'm going to kind of glaze over here because I assume you guys already know so what I plan to cover in this video in the subsequent few videos is the basics of displaying a geographical plane how to customize it and how to begin plotting on it uh pretty much all we're going to do is is simply plot some dots maybe in the future if I get around to it we can do some stuff like heat Maps uh but you need special files to do that and then once you have the special file it's really not too difficult so it's actually harder to plot your own data so anyway let's go ahead and get started and let's get what we need in that SPAC map so what you want to do is head over to your favorite internet browser and you're going to want to go to matplot li. org basemat and once you're there click on the download button and then it'll be like go here so you'll click here and uh you'll end up on Source Forge and you'll want to pick the latest version of basem map and then you can pick whatever you've got here there's the 64-bit 32bit and there's also just like the source down here so pick whichever one you uh are using if you've got a 64-bit python you need to download 64-bit if you've got 32-bit python uh you need to download a 32-bit and once you've got that all installed uh we can begin to work with base map so what you should always do once you think you've installed it you should bring over an interpreter real quick and do import or I'm sorry from mcore toolkit. basemap import capital b a map and as long as you don't throw any errors you've done it right so as long as you haven't let's continue with the tutorial so as you could probably guess that's what we're going to import here as well so we're going to say from npl toolkit. basap import import Bap now what we need to do is import matplot Li P plot as PLT you guys should be pretty familiar with this matplot li. pyplot as PLT not period now what we want to do is we want to set up our base map logic so what you can kind of think of this as is when you were building a figure in matplot lib and you were setting up maybe a subplot that's kind of what we're doing here is setting up our subplot so here's what we're going to do we're going to say m for a really really short equals capital b as map and the projection is going to be equal we're going to use Mill now what Mill is standing for is a Miller cylindrical projection if you don't care sorry it's time to learn some stuff basically the displaying of a map is there's I let's see there's about I don't know 20 or 30 different projections that you can use within base map so just depends on what you're looking for let me drag it over these this is the list here and then I'll pull it up so you can see the whole thing um so from there all the way down here and so um basically I can open up a few so you can kind of get an idea what I'm talking about when I say that each one has its own kind of stuff right so here is our Miller this is what our map will look like right so it's squarish but as you can see uh it gets kind of distorted especially up here this is kind of a distorted area we come over this is an asmal equidistant projection so uh there's that you've got this I don't even know how to say this pneumonic full disc anyway you get the idea so depending on like what exactly you want your um your chart to look like basically you can choose between all of these but for the purposes of this tutorial just to keep it as basic as possible we're going to use this Miller one which I believe is this one so um anyway just kind of be aware of the fact that there's just a ton of other projections but each one has um different stuff like it depends on like if you're if you're making a flight map let's say you kind of want your distance between the two uh between point a and point B to be at least visually quite you know pretty close and then but at the same time if you're just interested in the countries then you want the countries to be fairly proportionate to their actual size and you don't care so much about the oceans maybe just depends so there's just there's like a you know a projection for every size so that's that uh the next thing that we want to do is is specify the corners that we want um our projections so this is you know the full earth right but if we just wanted maybe the United States we would specify you know the coordinates here here here and here like a box but for now we're going to just do the a full a full size here just to keep things as simple as possible so the way this is is llcr n r l a t so this is lower left so LL lower left crn cor or C crnr Corner latitude equals uh 90 then upper right corner lat equals 90 back slash enter Then LL Corner lawn equals uh - 180 and then upper right corner lawn = 180 so we've got a full map here next thing we need is resolution equals c and that's um we'll talk about that probably in the next next video because I don't want to spend too much time explaining everything here um but basically that's how you know the level of uh granularity basically you're going to have but we'll get to that like I said so then um next thing you want to do is do M draw coast line empty parameters that's just obviously going to draw lines over the coast then we want to fill the continents so m. fill continents continents so basically you're originally just because you did this you would just have like a blank plot and you got to draw some Coast lines now you're going to fill in the continents and then m. draw map boundary and then we'll add a title same way you've always added titles uh so quick base B map example and then PLT doow and if we haven't thrown any errors or made any errors um this should work sure enough here is our basic projection just a quick example of how we can uh put something up real quick so anyway um that's your first chart definitely just wanted to put out a a chart get you guys going in the first video but uh the next stuff we're going to continue on in the next video so if that sounds interesting to you guys and you should continue on as always thanks for watching