将列表转换为double [英] converting a list to double
问题描述
大家好。我有一个名为linearRegression（）的函数。现在我正在完成这个功能atm。关于这个函数：该函数执行一个SQL查询，从我的数据库中名为Yahoo的表中获取一列。现在，这里的事情变得越来越模糊。我需要能够对这个结果集执行数学运算，即。找到rsquared值，斜率，平均值等.....但我现在不能在列表中做任何这个。我尝试将列表创建为特定类型列表列表，但无论出于什么原因，eclipse都给了我错误。我已经尝试将我的列表转换为多次加倍而没有任何结果。任何指导表示赞赏。
Hi again folks. I have a function called "linearRegression()" now I am along way from finishing this function atm. A little about this function: The function executes an SQL query grabbing a column from a table in my database called "Yahoo". Now here is where things are getting fuzzy for me. I need to be able to perform mathematical operations on this result set ie. finding the rsquared value, slope, average etc..... but i cannot do any of this on the list at is is now. I have tried created the list as a "type specific" list, but for whatever reason eclipse is giving me errors. I have tried converting my list to doubles numerous times without any results. Any guidance is appreciated.
推荐答案
再次大家好。我有一个名为linearRegression（）的函数。现在我正在完成这个功能atm。关于这个函数：该函数执行一个SQL查询，从我的数据库中名为Yahoo的表中获取一列。现在，这里的事情变得越来越模糊。我需要能够对这个结果集执行数学运算，即。找到rsquared值，斜率，平均值等.....但我现在不能在列表中做任何这个。我尝试将列表创建为特定类型列表列表，但无论出于什么原因，eclipse都给了我错误。我已经尝试将我的列表转换为多次加倍而没有任何结果。任何指导表示赞赏。
Hi again folks. I have a function called "linearRegression()" now I am along way from finishing this function atm. A little about this function: The function executes an SQL query grabbing a column from a table in my database called "Yahoo". Now here is where things are getting fuzzy for me. I need to be able to perform mathematical operations on this result set ie. finding the rsquared value, slope, average etc..... but i cannot do any of this on the list at is is now. I have tried created the list as a "type specific" list, but for whatever reason eclipse is giving me errors. I have tried converting my list to doubles numerous times without any results. Any guidance is appreciated.
对不起m8。没有当前的功能给我没有错误。但我不能对它进行数学运算。例如：
double sum = list（0）+ list（1）;
不起作用，因为列表元素是对象。我需要一种方法将它们转换成双打......这可能比我制作它容易得多。但到目前为止，重复的尝试除了雾之外什么也没做。我的代码。
Sorry m8. No that current function gives me no errors. But I cannot perform math operations on it. for example:
double sum = list(0) + list(1);
will not work because the list elements are objects. I need a way to convert them to doubles... this is probably much easier then I am making it. But thus far repeated attempts have done nothing but "fog" up my code.
对不起m8。没有当前的功能给我没有错误。但我不能对它进行数学运算。例如：
double sum = list（0）+ list（1）;
不起作用，因为列表元素是对象。我需要一种方法将它们转换成双打......这可能比我制作它容易得多。但到目前为止，重复的尝试除了雾之外什么也没做。我的代码。
Sorry m8. No that current function gives me no errors. But I cannot perform math operations on it. for example:
double sum = list(0) + list(1);
will not work because the list elements are objects. I need a way to convert them to doubles... this is probably much easier then I am making it. But thus far repeated attempts have done nothing but "fog" up my code.
不要使用代码字，这是一个论坛而不是聊天室:-)
并具体说明你的问题。
您确定列表中存储的内容可以解析为双倍吗？
然后查看此代码。
Don''t use code words, it''s a forum not a chatting room :-)
And be specific about your problem.
Are you sure that what you store in list that can be parsed as double?
Then have a look at this code.
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