Questions tagged [beginner]

For questions which concern getting started in Data Science or any of its related subdomains.

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4
votes
2answers
2k views

How to apply class weight to a multi-output model?

I have a model with 2 categorical outputs. The first output layer can predict 2 classes: [0, 1] and the second output layer can predict 3 classes: [0, 1, 2]. How can I apply different class weight ...
54
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3answers
69k views

RNN vs CNN at a high level

I've been thinking about the Recurrent Neural Networks (RNN) and their varieties and Convolutional Neural Networks (CNN) and their varieties. Would these two points be fair to say: Use CNNs to break ...
0
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1answer
37 views

Which Machine Learning methods would be good for a beginner-level Data Science project for described dataset? [closed]

I want to do my first beginner-level project regarding Data Science. I picked my data set which is described below. I want to make a Python script which will make some predictions on our data set ...
1
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0answers
35 views

How to deal with large datasets?

I have some experience with data science but I wanted some insight on how to deal with a very large dataset. I understand simply downloading it to your computer is not plausible so where do you even ...
0
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2answers
44 views

Finding Criminal Name in news?

We have news URLS, which we want to classify into crimes or non-crimes and further identify criminals by using NERs. For creating a model that identifies criminals, we tried SPacy which gave all the ...
2
votes
3answers
6k views

Determine useful features for machine learning model

I am working with a dataset with hundreds of features. I wish to create a simple machine learning model using 7-10 features from the original dataset. My question is this: What quantitative metrics ...
0
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2answers
132 views

Tips for checking data integrity / data sanity?

I've read a few vague articles and watched a couple of YouTube videos on data integrity and data sanity, but none of them have mentioned ways to actually check these on datasets. I am interested in ...
1
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1answer
50 views

Where to upload a source text to datamine matching contents with constraint?

I am even unsure if this is the correct category. I have very minimal programming knowledge. I am curious how can I get started for a project I have in mind. I want to upload a file to a webcrawler ...
1
vote
1answer
93 views

Why can't I use data augmentation with a pretrained convnet?

Reading Deep Learning with Python by François Chollet. In section 5.3.1, we've instantiated a pretrained convnet, VGG16, and are given two options to proceed: A) Running the convolutional base over ...
0
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2answers
30 views

Inspect false classified

Recently, I was able to train a simple classification algorithm (my first ML-Project) and I even got a pretty satisfying precision score. Now I am looking for a way to inspect, which datapoints in ...
-1
votes
1answer
34 views

Inputting Data for Machine Learning in PyTorch

I have scoured the internet and documentation, but have not yet been able to find a simple explanation of how to load data and/or simply type data into pytorch. I am just learning this library, and I ...
2
votes
1answer
30 views

How to define a neural model as linear or non linear

TL;DR: in what sense is the model of a neuron seen in the image above nonlinear? In chapter 1, section 1.3 MODELS OF A NEURON of Simon Haykin's Neural Networks book, the standard model of a single ...
0
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0answers
11 views

Piecewise-linear activation function definition doesn't correspond to graph found in textbook

This question is a duplicate of this question on StackOverflow, but it hasn't been answered in 2 years, which is why I'm re-posting it. If this isn't an appropriate way to go about this, please let me ...
0
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1answer
38 views

On Python is the `i` variable defined inherently? [closed]

I am new to this whole landscape, please need some hand holding at first, I can't find a beginner section. Can someone please tell me if i is defined inherently in ...
0
votes
1answer
28 views

What is the difference between the value -99 and NaN in a data column?

I am new to data science. I was looking into some datasets and I saw some values like -99, which I discovered later that it means that there is a missing value. Does this mean the same thing as NaN? ...
1
vote
1answer
45 views

Getting into data science and NLP outside of university

I'm almost 40. Four months ago I resigned from work to rest from stressing work and change my carerr direction. It took me some time to understand what I want to do and only then I started to learn ...
-1
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1answer
39 views

'Feature' definition

Precisely, what is a feature? Is it an attribute/property name or its value? E.g. would features examples be "name", "adress", ...? Or "Dorothy", "123 YellowBrick Road"?? If it is a property name, ...
2
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0answers
28 views

How does permutation of training data improve convergence time when training a perceptron or neural network model? [duplicate]

I'm currently studying some basic concepts regarding Deep Learning and Neural Networks with this material. When discussing the training algorithm for a perceptron, the author states that looping ...
2
votes
1answer
44 views

Mapping of categorical features into binary indicator features

I am currently reading an introductory machine learning book by Daumé (ch. 03, p. 30) and when discussing the mapping of categorical features with "n" possible values into "n" binary indicator ...
0
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0answers
25 views

Help with Tensorflow 2.0 beta not learning

Have a tabular data set and have done some graphical exploration with Orange 3. Attempted NN regression with Keras/TensorFlow 2.0 beta on Python 3.6.7. The problem is that TF 2.0 is not "learning" (...
0
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1answer
29 views

My network optimises for mean_squared_error, but the predictions are useless

After going through the tutorials of tensorflow I decided to do my own project. For this I did the following: I have scraped movie reviews from a polish site called filmweb. I got a dataset o 5400 ...
5
votes
2answers
521 views

Data scientist light?

Im a 26 year old guy with an MBA and I work as an ERP system administrator. I have been interested in the field of data science for a while now. I've always liked statistics and various analytical ...
1
vote
2answers
11k views

What is the difference between the training and testdata set?

What is the difference between the test and training data sets? As per blogs and papers I studied, what I understood is that we will have 100% data set that is divided into 2 sets (test data set is 30%...
3
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6answers
905 views

Where to start, which books [closed]

What is a good book or resource to start learning Artificial Intelligence ?
0
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1answer
186 views

Prerequisites for openCV [closed]

I am looking to start learning openCV to perform a car detection program. Should I know data science and/or machine learning stuff before going for openCV? If not, where can I start learning openCV ...
2
votes
1answer
30 views

Representing state in Q-Learning

I have a fairly simple game in which I wish to use Q-learning to train an agent, but I have some questions regarding state representation. I'm new to RL so bare with me: If you have a game where you ...
1
vote
2answers
84 views

Is Mac OS the most suitable OS for a beginner Data Scientist? [closed]

As far as I understand a data scientist should learn both Excel and Bash. And the golden mean is this case is Mac OS, because it has both. And later I can install Ubuntu on Macbook.
1
vote
1answer
322 views

xgboost performance with predicted values as input

I have predicted the probability of loss using different features. Now when I used this with a non-important feature to predict the probability of loss. The first one is very close. logloss was close ...
0
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0answers
22 views

Autoencoder and Dimensionality

I'm pretty confused with the input/output/dense portion of an autoencoder. So my data consists of a numpy array of a 9 categorical features which have all been one hot encoded. So the input would ...
8
votes
5answers
1k views

What does it mean when people say a cost function is something you want to minimize?

I am having a lot of trouble understanding this. Does it mean you should not use the cost function very often?
0
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1answer
22 views

Train, test and submission files - what am I supposed to do with all of them?

this might be very beginner's question. I'm working on Kaggle's HomeCredit Default Risk problem which has among others dataset train, test and submission files as can be seen in the link provided. The ...
0
votes
2answers
204 views

How to handle continuous values and a binary target?

This is going to be a very beginner's question. I have a datset of continues features like LoanAmount, LoanDuration(multiclass?), ... ClientIncome, ClientFreeSources, etc. and a binary target whether ...
1
vote
1answer
49 views

Data Exploration Tips & Tools

I am pretty new to the Data Science world and I am looking for some advices. One of the tasks that I have to do, is to go alone at a customer place for few days/weeks and dig into their data lake to ...
1
vote
1answer
27 views

MOOC importance [closed]

My problem is that at our masters program we have already been taught R, Statistics, Neural nets, Python (pandas, sklearn, etc). Also my master thesis is directly related to Deep Learning and Computer ...
4
votes
4answers
769 views

Data Science Career: From Researcher To Data Scientist

I’m currently working as a Research Assistant in Computer Science, specializing in both Human-Computer Interaction (HCI) and Health Informatics (HI) fields. As part of my role, I collect data from ...
1
vote
0answers
28 views

What are the introductory mathematics courses that are most pertinent to machine learning?

To provide more context to this question, I have found the following list of courses in order to learn calculus: Course | 18.01.1x | edX Course | 18.01.2x | edX Course | 18.01.3x | edX I also have ...
22
votes
2answers
7k views

How to deal with time series which change in seasonality or other patterns?

Background I'm working on a time series data set of energy meter readings. The length of the series varies by meter - for some I have several years, others only a few months, etc. Many display ...
5
votes
2answers
2k views

What is a policy in machine learning?

While I was reading the paper "Grounded Action Transformation for Robot Learning in Simulation", I came across the term "policy". Could someone explain to me what that actually is (in general and in ...
2
votes
5answers
1k views

How to compare Timeseries Sequences?

I have multiple time series sequences and I want for each new time series to find the most alike old one. I found that I can use the sum of errors between points. Is this a good approach? Is there a ...
0
votes
1answer
41 views

Timeseries of odds in race - how to pick a model

Being new to AI/ML I'd like some pointers to where to begin. I got data from horse races. Specifically, I got the odds for each runner during the race - ca 5 times per second. ...
1
vote
0answers
76 views

very large difference between cross_val and (multiple) r2 model evaluation

I did submit my first kaggle kernel, on the avocado dataset kernel link, I treated it like I should predict the avocado price so I splitted the dataset in a train & test set, fitted the model and ...
13
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7answers
1k views

I am a programmer, how do I get into field of Data Science?

First of all this term sounds so obscure. Anyways..I am a software programmer. One of the languages I can code is Python. Speaking of Data I can use SQL and can do Data Scraping. What I figured out ...
2
votes
3answers
2k views

Is there any book for modern optimization in Python?

I was reading Modern Optimization with R (Use R!) and wondering if a book like this exists in Python too? To be precise something that covers stochastic gradient descent and other advanced ...
3
votes
2answers
505 views

Can a single-layer ANN get XOR wrong?

I'm still pretty new to artificial neural networks. While I've played around with TensorFlow, I'm now trying to get the basics straight. Since I've stumbled upon a course which explains how to ...
4
votes
0answers
86 views

Which technologies and skills should the new generation of data scientists learn? [closed]

Having looked at various job requirements, I see that a lot of them require you to be an expert in Hadoop, use Spark but I am wondering how useful are these technologies (due to my lack of ...
1
vote
3answers
897 views

How to best forecast simple binary data? [closed]

I have a set of timeseries binary (boolean) data, with intervals of 1 day. Each day can either be 1 or 0 (true/false). What is the best way to forecast the next day/week's data based on the data I ...
0
votes
1answer
133 views

Chi-squared for continuous variables

I am using chi-squared to determine feature importance as I select features to train a supervised ML model. I create a contingency table for the feature/target, and feed this contingency table into ...
-1
votes
2answers
64 views

Guidance to create a machine learning alg to find multiple overlapping date over multiple period

i have a dataset of work period from a lot of people during multiple years and i would like to find the overlapping date between these periods, the data would look something like this: ...
7
votes
2answers
3k views

Which supervised learning algorithms are available for matching?

I'm working on a non-profit where we try to help potential university applicants by matching them with alumni that want to share their experience/wisdom and, at the moment, it is happening manually. ...
8
votes
3answers
657 views

What knowledge do I need in order to write a simple AI program to play a game?

I'm a B.Sc graduate. One of my courses was 'Introduction to Machine Learning', and I always wanted to do a personal project in this subject. I recently heard about different AI training to play games ...