有谁知道如何从csv文件加载数据?
对于代码示例, CPTestAppScatterPlotController.m 我从核心情节谷歌网站下载,可以随机绘制线图 生成初始数据x,y。
// Add some initial data
SMutableArray *contentArray = [NSMutableArray arrayWithCapacity:100];
NSUInteger i;
for ( i = 0; i < 60; i++ ) {
id x = [NSNumber numberWithFloat:1+i*0.05];
id y = [NSNumber numberWithFloat:1.2*rand()/(float)RAND_MAX + 1.2];
[contentArray addObject:[NSMutableDictionary
dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]];
}
self.dataForPlot = contentArray;
然后我修改了代码,
NSString *filePath = [[NSBundle mainBundle] pathForResource:@"ECG_Data" ofType:@"csv"];
NSString *myText = [NSString stringWithContentsOfFile:filePath encoding:NSUTF8StringEncoding error:nil ];
NSScanner *scanner = [NSScanner scannerWithString:myText];
[scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"\n, "]];
NSMutableArray *newPoints = [NSMutableArray array];
float time, data;
while ( [scanner scanFloat:&time] && [scanner scanFloat:&data] ) {
[newPoints addObject:
[NSMutableDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithFloat:time], @"time",
[NSNumber numberWithFloat:data], @"data",
nil]];
}
self.dataForPlot = newPoints;
似乎我的代码无法从csv文件中读取数据。 (ECG_Data.csv中有两列数据,一个用于时间,一个用于数据) 谁能给我一些建议??? 感谢!!!!
答案 0 :(得分:2)
http://cocoawithlove.com/2009/11/writing-parser-using-nsscanner-csv.html
这是开始创建CSV解析器的好地方。它包含示例代码和用户注释。