引擎
GPT-4
输入预览
[MAKE SURE YOU HAVE ACCESS TO THE CHAT-4 CODE INTERPRETER, AND UPLOAD YOUR CSV FILE.]
[Number of Days for Prediction]: 90
输出预览
Let's start by loading and inspecting the data.
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The data contains the following columns:
• Date: The date of the trading day.
• Open: The opening price of the stock on that day.
• High: The highest price of the stock on that day.
• Low: The lowest price of the stock on that day.
• Close: The closing price of the stock on that day.
• Adj Close: The adjusted closing price of the stock on that day, which adjusts the closing price for corporate actions such as dividends, stock splits, and new stock offerings.
• Volume: The number of shares traded on that day.
For our time series analysis, we'll use the 'Date' column as the index and the 'Close' prices to predict future values. Let's prepare the data accordingly.
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The data is now prepared for analysis. The 'Date' column has been set as the index and we will use the 'Close' price for our predictions.
Before proceeding to the SARIMA model, it's worth noting that this model requires stationary data. Stationarity is a property of time series data where the statistical properties (like mean, variance, and autocorrelation) are constant over time. If the data isn't stationary, we may need to transform it to make it so.
Let's check the stationarity of our data. We can do this visually by plotting the data and statistically by using the Augmented Dickey-Fuller (ADF) test. The null hypothesis of the ADF test is that the time series is non-stationary. So, if the p-value is less than the significance level (0.05), we reject the null hypothesis and infer that the time series is indeed stationary.
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[Image of a graph]
The p-value for the Augmented Dickey-Fuller test is approximately 0.43, which is larger than 0.05, meaning we cannot reject the null hypothesis that the series is non-stationary. This observation is also supported by the plot, which shows a clear upward trend in the data over time.
To make the series stationary, we will apply differencing, which is a common technique in time series analysis. Differencing a series involves subtracting the current value from the previous one. If this transformation is not enough to make the series stationary, we can apply a second round of differencing, which would subtract the current value from the value two time points ago, and so on.
Let's apply differencing and check the stationarity of the transformed series.
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[Image of a graph]
The p-value for the Augmented Dickey-Fuller test after differencing is 0.0, which is smaller than 0.05. This means we can reject the null hypothesis that the series is non-stationary, indicating that the differenced series is indeed stationary. This is also supported by the plot, which shows no clear trend in the differenced data.
Now that we have a stationary series, we can proceed to fit a SARIMA model. SARIMA stands for Seasonal Autoregressive Integrated Moving Average. It's a type of model that's used to predict future points in a time series. SARIMA models are denoted SARIMA(p,d,q)(P,D,Q)m, where:
• p and seasonal P: order of the autoregressive part
• d and seasonal D: order of differencing
• q and seasonal Q: order of the moving-average part
• m: the seasonality period
We already know that d=1 from our differencing step. To find the optimal values for the other parameters, we can use grid search and choose the parameters that minimize the AIC (Akaike Information Criterion), which measures the quality of a statistical model.
Let's find the optimal SARIMA parameters and fit the model. This could take some time as we're testing multiple combinations of parameters.
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The optimal SARIMA parameters found are:
• �=0p=0, �=1d=1, �=1q=1 for the non-seasonal components
• �=0P=0, �=1D=1, �=1Q=1, �=12m=12 for the seasonal components
These parameters resulted in the lowest AIC (Akaike Information Criterion) value of 6092.918, which suggests that this model will likely perform well in comparison to others.
Let's now fit the SARIMA model using these parameters and make predictions for the next 365 days.
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The model has generated predicted closing prices for the next 365 days. For example, the predicted closing price on the 1258th day from the last date in the dataset is approximately $129.98, with a 95% confidence interval ranging from approximately $124.44 to $135.52.
Let's visualize these predicted prices for the next 365 days.
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[Image of a graph]
The above graph shows the predicted closing prices for Amazon's stock over the next 365 days, as per the SARIMA model. The red line indicates the predicted prices, while the shaded area represents the 95% confidence interval.
Please note that these are statistical predictions based on past data and may not reflect future actual prices due to the unpredictable nature of the stock market. Factors such as market conditions, economic indicators, and company performance can significantly influence stock prices. Always consider these factors and consult with a financial advisor before making investment decisions.