Python Data Science Tutorial #10 - Scatter Plots with Matplotlib

what is going on guys welcome to this Python tutorial series for data science in today's video we're going to learn about scatter plot so plotting individual points instead of functions or bar charts or pie charts so let us get into the code so as always the first thing that we're going to do is to import numpy and math 11 after that we're going to define the ax and the y coordinates because when we do a scatter plot we're dealing with individual data points we're not dealing with functions we're not dealing with bar charts we're dealing with individual points so for example if you have a data frame with I don't know 10 columns and you take one row that would be one data point now if you have 10 columns it would be one data point in ten dimensions but we're going to deal with just two dimensions so we're going to have the ax value and the Y value and this can be whatever you want for example the height and the weight of a person would be one data point so you would have the height or the weight on the y axis and the height on the x axis and then you would have the individual data points spread over this graph and then you could look for correlations for example so scatter plots are just plotting individual data points that's basically it and to generate them we're just going to say x equals NP dot random rant and we're going to generate 50 random values for X and 50 random values for random for y and then we're just going to use them as the coordinates for a point so the first x coordinate and the first y coordinate would be the first data point and to now plot the scatter plot we're just going to say PLT scatter and ax and y that's basically it and then we're going to say PLT dot show so as you can see this is a scatter we have all these individual data points of course what we can also do is we can just define them ourselves so if we don't want to or randomly generate them we can just create lists I think it actually should work with ordinary Python lists so for example let's say and we need 30 40 and maybe again 20 and then y equals I don't know 5 7 3 2 1 4 6 and then we should be able to plot that as well hopefully yeah so this would be of course first of all not that many data points but also I chose the values manually so whatever you need you can define your values the way you want but a scatter plot works basically like that so now we're going to do is we're going to adjust the style of our scatter plot a little bit because when you look at it we have some blue dots and dad's basically it and maybe we don't want to have dots maybe we want to have a different color we want to have a different marker we want to have a different size and this is all or these are all things that we can adjust in the scatter function so for example if I want to change the color I can just say C equals and then rad for example I think rad should work but otherwise R should work yeah rad works so now we have rad dots but maybe I'm not interested in dots maybe I want to have crosses so I can say marker equals and then provide a string with an axe symbol in there and it should change the marker to X as you can see and there are a bunch of different markers there are a lot of different markers actually so for example one would be the triangle here triangle facing up would be just a basic power sign we could also have triangles facing down there should be the V character and actually you can just google all these but you have very a lot of different options for example you can use two you can use three four five four different markers so two would be that and for example five would be something else and of course you can just okay five we don't have five unfortunately I think age should be hexagon or something like that I'm not sure but I think so yeah as you can see it is and now what we're going to do is we're going also to change the size so I'm going to say as equals and to be honest I don't know what size was default so I'm going to go with one and see if it okay one is less than what we had so let's take a hundred maybe I hope that's not too big but it should work yeah that's fine so with the as parameter we can adjust the size of the scatterplot or of the individual dots or not dots of the individual markers actually of course this works with all kinds of markers and that's how you basically style your scatterplot now why are scatter plots even important because when we get into machine learning later on we're going to train for example some linear regression models or classification models and of course the linear regression line is a function and the classification is also not a data point but the individual things that we're classifying or that we're using as a training or testing data are actually data points and data points need to be plotted with the scatter function because they're individual points there enough lines they're not polygons certain of areas they're just individual data points and this is why we need to scatter function so this is basically plotting scatter plots in Python so this was the tutorial on scatter plots I know it was quite a short video but it's fine because we covered all the material and we're going to use scatter plots in the future and then we're maybe going to learn a little bit more about them but for now that's enough so if you enjoyed this video if you learned something if you liked it hit the like button for me also feel free to ask questions and give feedback in the comment section down below and course as always subscribe to his channel if you want to see more and thank you very much for watching see you in the next video bye [Music] you