Update parameter.md

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Tianqi Chen 2015-05-04 10:51:51 -07:00
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@ -56,7 +56,7 @@ From xgboost-unity, the ```bst:``` prefix is no longer needed for booster parame
- "binary:logistic" --logistic regression for binary classification, output probability - "binary:logistic" --logistic regression for binary classification, output probability
- "binary:logitraw" --logistic regression for binary classification, output score before logistic transformation - "binary:logitraw" --logistic regression for binary classification, output score before logistic transformation
- "count:poisson" --poisson regression for count data, output mean of poisson distribution - "count:poisson" --poisson regression for count data, output mean of poisson distribution
- max_delta_step is set to 1 by default in poisson regression(used to safeguard optimization) - max_delta_step is set to 0.7 by default in poisson regression (used to safeguard optimization)
- "multi:softmax" --set XGBoost to do multiclass classification using the softmax objective, you also need to set num_class(number of classes) - "multi:softmax" --set XGBoost to do multiclass classification using the softmax objective, you also need to set num_class(number of classes)
- "multi:softprob" --same as softmax, but output a vector of ndata * nclass, which can be further reshaped to ndata, nclass matrix. The result contains predicted probability of each data point belonging to each class. - "multi:softprob" --same as softmax, but output a vector of ndata * nclass, which can be further reshaped to ndata, nclass matrix. The result contains predicted probability of each data point belonging to each class.
- "rank:pairwise" --set XGBoost to do ranking task by minimizing the pairwise loss - "rank:pairwise" --set XGBoost to do ranking task by minimizing the pairwise loss