specify or read the range of the values, ....

 specify or read the max min... useful if you want to make 2 graph
based on the same values, otherwise they would be inconsistent between
them, for example graph of download has max 20 min 10 , and graph of
updates has max 5 and min 0, without that the 20 and the 5 would be in
the same place

        MPGraphValuesRange downloadRange=[MPPlot rangeForValues:values];
        MPGraphValuesRange updateRange=[MPPlot rangeForValues:upValues];

        MPGraphValuesRange range=MPGetBiggestRange(downloadRange,
updateRange);

        graph.valueRanges=range;
        updateGraph.valueRanges=range;

Author: MP0w

MPPlot.h

@@ -24,6 +24,34 @@ typedef NS_ENUM(NSUInteger, MPPlotType) {
 typedef CGFloat(^GraphPointsAlgorithm)(CGFloat x);
 
 
+struct _MPValuesRange {
+    CGFloat max;
+    CGFloat min;
+};
+
+typedef struct _MPValuesRange MPGraphValuesRange;
+
+NS_INLINE MPGraphValuesRange MPMakeGraphValuesRange(CGFloat min, CGFloat max) {
+    MPGraphValuesRange r;
+    r.min = min;
+    r.max = max;
+    return r;
+}
+
+NS_INLINE BOOL MPValuesRangeNULL(MPGraphValuesRange r) {
+    return r.min==CGFLOAT_MIN && r.max==CGFLOAT_MAX;
+}
+
+NS_INLINE MPGraphValuesRange MPGetBiggestRange(MPGraphValuesRange r1,MPGraphValuesRange r2) {
+    
+    MPGraphValuesRange r;
+    
+    r.min=(r1.min<r2.min ? r1.min : r2.min);
+    r.max=(r1.max>r2.max ? r1.max : r2.max);
+    
+    return r;
+}
+
 @protocol MPDetailView <NSObject>
 
 - (void)setText:(NSString *)text;
@@ -54,24 +82,25 @@ typedef CGFloat(^GraphPointsAlgorithm)(CGFloat x);
 // Abstract Class
 
 + (id)plotWithType:(MPPlotType)type frame:(CGRect)frame;
-
++ (MPGraphValuesRange)rangeForValues:(NSArray *)values;
 
 
 @property (nonatomic,copy) NSArray *values; // array of NSNumber or NSString
 @property (nonatomic,retain) UIColor *graphColor; // color of the line
 @property (nonatomic,assign) CGFloat lineWidth;
 @property (nonatomic,assign) BOOL waitToUpdate;
 @property (nonatomic,assign) CGFloat animationDuration;
+@property (nonatomic,assign) MPGraphValuesRange valueRanges; // specify or read the max min... useful if you want to make 2 graph based on the same values, otherwise they would be inconsistent between them, for example graph of download has max 20 min 10 , and graph of updates has max 5 and min 0, without that the 20 and the 5 would be in the same place
 
-@property (nonatomic,readwrite) UIView<MPDetailView> *detailView;
 
 // detail View customization
+@property (nonatomic,readwrite) UIView<MPDetailView> *detailView;
 @property (nonatomic,retain) UIColor *detailBackgroundColor;
 @property (nonatomic,retain) UIColor *detailTextColor;
-
 @property (nonatomic,retain) NSNumberFormatter *detailLabelFormatter;
 
 
+
 - (void)animate;
 
 - (void)setAlgorithm:(GraphPointsAlgorithm)customAlgorithm numberOfPoints:(NSUInteger)numberOfPoints;

MPPlot.m

@@ -12,11 +12,39 @@
 
 @implementation MPPlot
 
++ (MPGraphValuesRange)rangeForValues:(NSArray *)values{
+    
+    CGFloat min,max;
+    
+    min=max=[[values firstObject] floatValue];
+    
+    
+    for (NSInteger i=0; i<values.count; i++) {
+        
+        CGFloat val=[[values objectAtIndex:i] floatValue];
+        
+        if (val>max) {
+            max=val;
+        }
+        
+        if (val<min) {
+            min=val;
+        }
+        
+    }
+    
+    
+    
+    return MPMakeGraphValuesRange(min, max);
+}
+
+
 
 - (id)init
 {
     self = [super init];
     if (self) {
+        self.valueRanges=MPMakeGraphValuesRange(CGFLOAT_MIN, CGFLOAT_MAX);
         NSAssert(![self isMemberOfClass:[MPPlot class]], @"You shouldn't init MPPlot directly, use the class method plotWithType:frame:");
     }
     return self;
@@ -26,6 +54,7 @@ - (id)initWithFrame:(CGRect)frame
 {
     self = [super initWithFrame:frame];
     if (self) {
+        self.valueRanges=MPMakeGraphValuesRange(CGFLOAT_MIN, CGFLOAT_MAX);
         NSAssert(![self isMemberOfClass:[MPPlot class]], @"You shouldn't init MPPlot directly, use the class method plotWithType:frame:");
     }
     return self;
@@ -71,35 +100,25 @@ - (void)drawRect:(CGRect)rect{
 
 
 
-- (NSMutableArray *)pointsForArray:(NSArray *)dict{
-    
-    CGFloat min,max,avg;
+- (NSMutableArray *)pointsForArray:(NSArray *)values{
 
-    min=max=[[dict firstObject] floatValue];
+    CGFloat min,max;
 
 
-    for (NSInteger i=0; i<dict.count; i++) {
-        
-        CGFloat val=[[dict objectAtIndex:i] floatValue];
-        
-        if (val>max) {
-            max=val;
-        }
-        
-        if (val<min) {
-            min=val;
-        }
-        
-        avg+=val;
+    if (MPValuesRangeNULL(self.valueRanges)) {
+        _valueRanges=[MPPlot rangeForValues:values];
+        min=_valueRanges.min;
+        max=_valueRanges.max;
+    }else{
+        max=_valueRanges.max;
+        min=_valueRanges.min;
     }
 
-    avg/=dict.count;
-    
 
     NSMutableArray *pointsArray=[[NSMutableArray alloc] init];
 
     if(max!=min){
-        for (NSString *p in dict) {
+        for (NSString *p in values) {
 
             CGFloat val=[p floatValue];
 
@@ -133,6 +152,14 @@ - (void)setValues:(NSArray *)values{
 
 }
 
+- (void)setValueRanges:(MPGraphValuesRange)valueRanges{
+    
+    _valueRanges=valueRanges;
+    
+    if (!MPValuesRangeNULL(valueRanges) && self.values) {
+        points=[self pointsForArray:self.values];
+    }
+}
 
 
 - (void)setAlgorithm:(GraphPointsAlgorithm)customAlgorithm numberOfPoints:(NSUInteger)numberOfPoints{