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如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注C++内核技术
...aking sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply looking for a “good enough” algorithm for your problem, or a place to start, here are some general guidelines I’ve found to work well over the year...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注C++内核技术
...aking sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply looking for a “good enough” algorithm for your problem, or a place to start, here are some general guidelines I’ve found to work well over the year...
如何选择机器学习算法 - 大数据 & AI - 清泛网移动版 - 专注C++内核技术
...aking sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply looking for a “good enough” algorithm for your problem, or a place to start, here are some general guidelines I’ve found to work well over the year...
如何选择机器学习算法 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...aking sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply looking for a “good enough” algorithm for your problem, or a place to start, here are some general guidelines I’ve found to work well over the year...
如何选择机器学习算法 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...aking sure to try different parameters within each algorithm as well), and select the best one by cross-validation. But if you’re simply looking for a “good enough” algorithm for your problem, or a place to start, here are some general guidelines I’ve found to work well over the year...
Pass a data.frame column name to a function
...(x[,column])
}
fun1(df, "B", max)
Alternatively, using [[ also works for selecting a single column at a time:
df <- data.frame(A=1:10, B=2:11, C=3:12)
fun1 <- function(x, column){
max(x[[column]])
}
fun1(df, "B")
...
Error: “The sandbox is not in sync with the Podfile.lock…” after installing RestKit with cocoapods
...hat by updating CocoaPods.
I. Project Cleanup
In the project navigator, select your project
Select your target
Remove all libPods*.a in Build Phases > Link Binary With Libraries
II. Update CocoaPods
Launch Terminal and go to your project directory.
Update CocoaPods using the command pod in...
Unable to cast object of type 'System.DBNull' to type 'System.String`
... even both. If the WHERE does not match any row, you'll get a null, if the selected row has NULL in that column, the return value is System.DBNull.
– Alexander
May 27 '14 at 7:52
...
How to reshape data from long to wide format
...mes(df) <- unique(dat1$name)
df
sqldf package:
library(sqldf)
sqldf('SELECT name,
MAX(CASE WHEN numbers = 1 THEN value ELSE NULL END) x1,
MAX(CASE WHEN numbers = 2 THEN value ELSE NULL END) x2,
MAX(CASE WHEN numbers = 3 THEN value ELSE NULL END) x3,
MAX(CASE WHEN numbe...
Closing Database Connections in Java
...ent statement = connection.createStatement()) {
String sqlToExecute = "SELECT * FROM persons";
try (ResultSet resultSet = statement.execute(sqlToExecute)) {
if (resultSet.next()) {
System.out.println(resultSet.getString("name");
}
}
} catch (SQLException e) {
...