下列代码是如何读入一个稀疏矩阵的，
0
悬赏园豆：10
[已解决问题]
解决于 2011-11-25 08:39
int *readMatrix(char *fname, sparseStruct *mat, int &numEmptyCol, int formatType, char *scalingType)
// read in a sparse matrix from files into 'mat' and return #empty vectors and an array of empty vector IDs
{
char filename[FILENAME_LENGTH];
//clock_t start_clock, finish_clock;
sprintf(filename, "%s%s", fname, "_dim");
std::ifstream dimFile(filename);
if (dimFile == 0)
cout << " !!! File open error: " << filename << " !!!" << endl << endl;
sprintf(filename, "%s%s", fname, "_row_ccs");
std::ifstream rowPtrFile(filename);
if (rowPtrFile == 0)
cout << " !!! File open error: " << filename << " !!!" << endl << endl;
sprintf(filename, "%s%s", fname, "_col_ccs");
std::ifstream colIdxFile(filename);
if (colIdxFile == 0)
cout << " !!! File open error: " << filename << " !!!" << endl << endl;
sprintf(filename, "%s%s", fname, "_");
if (formatType == 0)
sprintf(filename, "%s%s", filename, TXX_SCALING);
else
sprintf(filename, "%s%s", filename, TFN_SCALING);
sprintf(filename, "%s%s", filename, "_nz");
std::ifstream valFile(filename);
if (valFile == 0)
cout << " !!! File open error: " << filename << " !!!" << endl;
if (dimFile == 0 || rowPtrFile == 0 || colIdxFile == 0 || valFile == 0){
cout << " !!! Matrix file " << fname << "_* has missing file(s) !!!" << endl;
exit(EXIT_FAILURE);
}
//data.width(MAX_DESC_STR_LENGTH);
//data >> mat->descString;
//data >> mat->numCol >> mat->numRow >> mat->numVal;
//start_clock = clock();
cout << " Reading dimension file ... " << endl;
dimFile >> mat->numRow >> mat->numCol >> mat->numVal;
dimFile.close();
mat->colPtr = new int[mat->numCol+1];
mat->rowIdx = new int[mat->numVal];
mat->value = new double[mat->numVal];
//space used for storing the sparse matrix is as follows
memoryUsed += (mat->numCol + 1 + mat->numVal) * sizeof(int) + mat->numVal * sizeof(double);
//it is necessary to handle empty vectors separately
int pre = -1;
int *tempEmptyColId = new int[mat->numCol], *emptyColId;
numEmptyCol = 0;
cout << " Reading column pointer file ... " << endl;
for (int i = 0; i < mat->numCol+1; i++){
colIdxFile >> (mat->colPtr)[i];
if ((mat->colPtr)[i] == pre){
tempEmptyColId[numEmptyCol] = i - 1;
numEmptyCol++;
}
pre = (mat->colPtr)[i];
}
colIdxFile.close();
emptyColId = new int[numEmptyCol+1];
for(int i = 0; i < numEmptyCol; i++)
emptyColId[i] = tempEmptyColId[i];
emptyColId[numEmptyCol] = mat->numCol;
delete [] tempEmptyColId;
cout << " Reading row index file ... " << endl;
for (int i = 0; i < mat->numVal; i++)
rowPtrFile >> (mat->rowIdx)[i];
rowPtrFile.close();
cout << " Reading non-zero value file ... " << endl;
for (int i = 0; i < mat->numVal; i++)
valFile >> (mat->value)[i];
valFile.close();
cout << endl;
//finish_clock = clock();
//cout << "Reading file time: " << (finish_clock - start_clock) / 1e6 << " seconds." << endl;
if (numEmptyCol == 0)
cout << " !!! No empty col found !!!" << endl;
else {
cout << " !!! " << numEmptyCol << " empty col(s) found !!!" << endl;
for(int i = 0; i < numEmptyCol; i++)
cout << emptyColId[i] << " ";
cout << endl;
}
return emptyColId;
}
mat是一个结构变量，存储file中的稀疏矩阵，在Reading column pointer file 时遇到一些问题，比如一个稀疏矩阵
0 2 4 0 1
3 2 0 0 0
0 0 4 0 0
2 3 0 0 0
column pointer file的内容应该是什么？
最佳答案
0
童靴，请把你要解决的问题描述清楚点。
你贴出的代码结构也不理想，叫人怎么读你的代码呢:)
比如函数说明吧
int *readMatrix(char *fname, sparseStruct *mat, int &numEmptyCol, int formatType, char *scalingType)
好歹要写点注释吧，哪些是输出信息，哪些是输入信息，返回值是什么，
sparseStruct 定义呢？
另外，初略估计了一下单这个函数大概有80到90行代码，函数体大了点，且函数体中缺少必要的注释和分段，建议关键的环节分段并添加必要的注释。
大家都很乐意帮你解答你的问题，但是可能有些大牛看到你的问题就退却了;)
建议重新组织一下你的问题，也许在组织问题的过程中你自己就把这个问题给解决了，这是很有可能的。
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