time series forecasting


Linear, Machine Learning and Probabilistic Approaches for Time Series Analysis

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In this post, we consider different approaches for time series modeling. The forecasting approaches using linear models, ARIMA alpgorithm, XGBoost machine learning algorithm are described. Results of different model combinations are shown. For probabilistic modeling the approaches using copulas and Bayesian inference are considered. Time series analysis, especially forecasting, is an important problem of modern predictive analytics.


Automated Feature Engineering for Time Series Data

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Most machine learning algorithms today are not time-aware and are not easily applied to time series and forecasting problems. Leveraging advanced algorithms like XGBoost, or even linear models, typically requires substantial data preparation and feature engineering – for example, creating lagged features, detrending the target, and detecting periodicity. The preprocessing required becomes more difficult in the common case where the problem requires predicting a window of multiple future time points. As a result, most practitioners fall back on classical methods, such as ARIMA or trend analysis, which are time-aware but less expressive. This article covers the best practices for solving this challenge, by introducing a general framework for developing time series models, generating features and preprocessing the data, and exploring the potential to automate this process in order to apply advanced machine learning algorithms to almost any time series problem.


Time series Forecasting in Machine Learning – 99XTechnology – Medium

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Understanding timely patterns/characteristics in data are becoming very critical aspect in analyzing and describing trends in business data . Example Use case 1: Fitness device market is built around buy people to help track fitness related data to monitor effectiveness of their fitness exercises. Example Use Case 2: Sales growth of a product over period of time is a good indicator of sales performance of a product manufacturing company. A typical time series model can exhibits different patterns. Therefor it is important to understand components of a time series in detail .


Python Overtaking R?

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He uses statistics from Google Trends, Indeed job search terms, and Analytic Talent (DSC job database) to conclude that Python has overtaken R. One is led to ask if one group of users (say Python's) is a more active googler. Indeed, the search term analyzed is "Python Data Science." From this poll, they found out that "in 2017 Python ecosystem overtook R as the leading platform for Analytics, Data Science, Machine Learning." So, maybe Python is overtaking R. Despite this, I learned reading comments, that R is still preferred for tasks like survival analysis, time series forecasting, glmnet, Bayesian model averaging, and hierarchical modeling thanks to its well developed statistical packages.


Time Series Forecasting with the Long Short-Term Memory Network in Python - Machine Learning Mastery

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A line plot of the test dataset (blue) compared to the predicted values (orange) is also created showing the persistence model forecast in context. It takes a NumPy array of the raw time series data and a lag or number of shifted series to create and use as inputs. The trend can be removed from the observations, then added back to forecasts later to return the prediction to the original scale and calculate a comparable error score. Running the example first prints the first 5 rows of the loaded data, then the first 5 rows of the scaled data, then the first 5 rows with the scale transform inverted, matching the original data.


Python Overtaking R?

@machinelearnbot

He uses statistics from Google Trends, Indeed job search terms, and Analytic Talent (DSC job database) to conclude that Python has overtaken R. One is led to ask if one group of users (say Python's) is a more active googler. Indeed, the search term analyzed is "Python Data Science." From this poll, they found out that "in 2017 Python ecosystem overtook R as the leading platform for Analytics, Data Science, Machine Learning." So, maybe Python is overtaking R. Despite this, I learned reading comments, that R is still preferred for tasks like survival analysis, time series forecasting, glmnet, Bayesian model averaging, and hierarchical modeling thanks to its well developed statistical packages.


Time Series Forecasting With Prophet

@machinelearnbot

It can be used for time series modeling and forecasting trends into the future. Unlike typical time-series methods like ARIMA (which are considered generative models), Prophet uses something called an additive regression model. I haven't dug into any of the math, but based on the description in their introductory blog post, Prophet builds separate components for the trend, yearly seasonality, and weekly seasonality in the time series (with holidays as an optional fourth component). One can imagine variables that could be used along with the time series to further improve the forecast (for example, a variable indicating if Peyton Manning had just won a game, or had a particularly good performance, or appeared in some news articles).


New Book: Time Series Forecasting With Python

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Time series forecasting is different from other machine learning problems. The key difference is the fixed sequence of observations and the constraints and additional structure this provides. In this mega Ebook written in the friendly Machine Learning Mastery style that you're used to, finally cut through the math and specialized methods for time series forecasting. Using clear explanations, standard Python libraries and step-by-step tutorials you will discover how to load and prepare data, evaluate model skill, and implement forecasting models for time series data.


How to Use Dropout with LSTM Networks for Time Series Forecasting - Machine Learning Mastery

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Dropout is a regularization method where input and recurrent connections to LSTM units are probabilistically excluded from activation and weight updates while training a network. We can see that on average this model configuration achieved a test RMSE of about 92 monthly shampoo sales with a standard deviation of 5. In this case, the diagnostic plot shows a steady decrease in train and test RMSE to about 400-500 epochs, after which time it appears some overfitting may be occurring. Running the updated diagnostic creates a plot of the train and test RMSE performance of the model with input dropout after each training epoch.


Linear, Machine Learning and Probabilistic Approaches for Time Series Analysis

@machinelearnbot

For arbitrary chosen store (Store 285) we received RMSE 0.11 for ARIMA model, RMSE 0.107 for XGBoost model and RMSE 0.093 for linear blending of ARIMA and XGBoost models. We also studied the case of time series forecasting using XGBoost model with time series approach and xgboost model based on independent and identically distributed variables. For arbitrary chosen store (Store 95) we received RMSE 0.138 for XGBoost model with time series approach and RMSE 0.118 for XGBoost model with i.i.d approach. Let us consider such features of sales time series as sales (variable logSales), mean sales per day for store (variable meanLogSales) and promo action (variable Promo).