importdata小提琴：http://jsfiddle.net/j40ucf6m/1/
与我最近提出的问题相关：P ..我刚发现npc_objects = {};
TURKEYLENGTH = (Math.max.apply(Math, Object.keys(npc_objects))) + 1;
console.log(TURKEYLENGTH);
实际上是一个数值。我正在尝试为它添加另一个数值，但它仍然会返回-Infinity。我试图在括号内移动+1。例如-Infinity
答案 0 :(得分：6)
除非您将Infinity添加到-Infinity，否则您将始终得到答案-Infinity（向Infinity添加NaN会给您-Infinity + 1）。如果我们知道-Infinity等于什么，我们就知道// Function detectAndDisplay
void detectAndDisplay(Mat frame)
{
std::vector<Rect> faces;
Mat frame_gray;
Mat crop;
Mat res;
Mat gray;
string text;
stringstream sstm;
cvtColor(frame, frame_gray, COLOR_BGR2GRAY);
equalizeHist(frame_gray, frame_gray);
// Detect faces
face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0 | CASCADE_SCALE_IMAGE, Size(30, 30));
// Set Region of Interest
cv::Rect roi_b;
cv::Rect roi_c;
size_t ic = 0; // ic is index of current element
int ac = 0; // ac is area of current element
size_t ib = 0; // ib is index of biggest element
int ab = 0; // ab is area of biggest element
for (ic = 0; ic < faces.size(); ic++) // Iterate through all current elements (detected faces)
{
roi_c.x = faces[ic].x;
roi_c.y = faces[ic].y;
roi_c.width = (faces[ic].width);
roi_c.height = (faces[ic].height);
ac = roi_c.width * roi_c.height; // Get the area of current element (detected face)
roi_b.x = faces[ib].x;
roi_b.y = faces[ib].y;
roi_b.width = (faces[ib].width);
roi_b.height = (faces[ib].height);
ab = roi_b.width * roi_b.height; // Get the area of biggest element, at beginning it is same as "current" element
if (ac > ab)
{
ib = ic;
roi_b.x = faces[ib].x;
roi_b.y = faces[ib].y;
roi_b.width = (faces[ib].width);
roi_b.height = (faces[ib].height);
}
crop = frame(roi_b);
resize(crop, res, Size(128, 128), 0, 0, INTER_LINEAR); // This will be needed later while saving images
cvtColor(crop, gray, CV_BGR2GRAY); // Convert cropped image to Grayscale
// Form a filename
filename = "";
stringstream ssfn;
ssfn << filenumber << ".png";
filename = ssfn.str();
filenumber++;
imwrite(filename, gray);
printf("filename");
Point pt1(faces[ic].x, faces[ic].y); // Display detected faces on main window - live stream from camera
Point pt2((faces[ic].x + faces[ic].height), (faces[ic].y + faces[ic].width));
rectangle(frame, pt1, pt2, Scalar(0, 255, 0), 2, 8, 0);
}
// Show image
/*sstm << "Crop area size: " << roi_b.width << "x" << roi_b.height << " Filename: " << filename;
text = sstm.str();
putText(frame, text, cvPoint(30, 30), FONT_HERSHEY_COMPLEX_SMALL, 0.8, cvScalar(0, 0, 255), 1, CV_AA);
imshow("original", frame);
if (!crop.empty())
{
imshow("detected", crop);
}
else
destroyWindow("detected");*/
等于什么（作为数字），这将使它成为有限数而不是无限数
答案 1 :(得分：2)
正如旁注，因为我们谈论的是javascript，
Infinity 之前有一个值。
我没有关于它的资源，但似乎Infinity之前的最大值是-179769313486231580793728971405303415079934132710037826936173778980444968292764750946649017977587207096330286416692887910946555547851940402630657488671505820681908902000708383676273854845817711531764475730270069855571366959622842914819860834936475292719074168444365510704342711559699508093042880177904174497791.99999 //+ infinity of 9。
您可以使用相同的数字*-1在-∞
在浮点数变成int之前还有一个悬崖，看一下片段。
var cliffBeforeInfinity = 179769313486231580793728971405303415079934132710037826936173778980444968292764750946649017977587207096330286416692887910946555547851940402630657488671505820681908902000708383676273854845817711531764475730270069855571366959622842914819860834936475292719074168444365510704342711559699508093042880177904174497791.99999; //+ infinity of 9
var realInfinity= 179769313486231580793728971405303415079934132710037826936173778980444968292764750946649017977587207096330286416692887910946555547851940402630657488671505820681908902000708383676273854845817711531764475730270069855571366959622842914819860834936475292719074168444365510704342711559699508093042880177904174497792;
var almost_zero = 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000024703282292062327208828439643411068618252990130716238221279284125033775363510437593264991818081799618989828234772285886546332835517796989819938739800539093906315035659515570226392290858392449105184435931802849936536152500319370457678249219365623669863658480757001585769269903706311928279558551332927834338409351978015531246597263579574622766465272827220056374006485499977096599470454020828166226237857393450736339007967761930577506740176324673600968951340535537458516661134223766678604162159680461914467291840300530057530849048765391711386591646239524912623653881879636239373280423891018672348497668235089863388587925628302755995657524455507255189313690836254779186948667994968324049705821028513185451396213837722826145437693412532098591327667236328125001;
var zero = 0.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000247032822920623272088284396434110686182529901307162382212792841250337753635104375932649918180817996189898282347722858865463328355177969898199387398005390939063150356595155702263922908583924491051844359318028499365361525003193704576782492193656236698636584807570015857692699037063119282795585513329278343384093519780155312465972635795746227664652728272200563740064854999770965994704540208281662262378573934507363390079677619305775067401763246736009689513405355374585166611342237666786041621596804619144672918403005300575308490487653917113865916462395249126236538818796362393732804238910186723484976682350898633885879256283027559956575244555072551893136908362547791869486679949683240497058210285131854513962138377228261454376934125320985913276672363281245;
var p = document.querySelector('p');
p.innerHTML+='cliff Before Infinity : '+cliffBeforeInfinity;
p.innerHTML+='<br>';
p.innerHTML+='Infinity : '+ realInfinity;
p.innerHTML+='<br>';
p.innerHTML+='cliff before -Infinity : '+cliffBeforeInfinity*-1;
p.innerHTML+='<br>';
p.innerHTML+='-Infinity : '+realInfinity*-1;
p.innerHTML+='<br>';
p.innerHTML+='almost zero : '+almost_zero;
p.innerHTML+='<br>';
p.innerHTML+='zero : '+ zero;<p></p>