matlab if(~isempty(I)) movobj.I(1:nframes) = struct('cdata', [], 'colormap', []); else movobj.I = []; end是什么意思
时间: 2024-05-29 21:13:32 浏览: 21
这是一段 MATLAB 代码,其中 if(~isempty(I)) 表示如果 I 变量不为空,即存在一个结构体数组,那么 movobj.I(1:nframes) 将被赋值为一个结构体数组,其中每个结构体包含两个字段:cdata 和 colormap。如果 I 变量为空,则 movobj.I 被赋值为一个空数组。
相关问题
约瑟夫环改错class Node: def __init__(self,data): self.data=data self.next=Noneclass linklist: def __init__(self): self.head=None self.data=None def isEmpty(self): if self.head: return False else: return True def length(self): if self.isEmpty(): return 0 else: t = self.head n = 1 while t.next: if t.next == self.head: break t = t.next n = n + 1 return n def addhead(self,data): node = Node(data) if self.isEmpty(): self.head = node self.tail = self.head else: node.next = self.head self.head = node self.tail.next = self.head def addtail(self,data): node=Node(data) if self.isEmpty(): self.addhead(data) else: t=self.head n=1 l=self.length() while n<l: n=n+1 t=t.next t.next=node node.next=self.head self.tail=node def delete(self,index): if self.isEmpty(): print("The linked list is empty") else: t = self.head l = self.length() if index == 0: self.head = t.next self.tail.next = self.head elif index == l - 1: n = 1 while n < l - 1: t = t.next n = n + 1 t.next = self.head self.tail = t elif index > l - 1: print("Out of range") elif index < 0: print("Wrong operation") else: n = 1 while n < index - 1: t = t.next n = n + 1 a = t.next.next t.next = a def insert(self,data,index): l = self.length() if index == 0 or self.isEmpty(): self.addhead(data) elif index >= l: self.addtail(data) else: node = Node(data) t = self.head n = 1 while n < index - 1: t = t.next n = n + 1 a = t.next t.next = node node.next = a def search(self,a): t=self.head for i in range(a): t=t.next return t.data def form(self,datalist): self.addhead(datalist[0]) for i in range(1,len(datalist)): self.addtail(datalist[i]) t = self.head while t.next != self.head: t = t.nextn,p=map(int,input().split(' '))data=[]p=p-1for i in range(1,n+1): data.append(i)print(data)datalist=[]for i in range(len(data)): datalist.append(int(data[i]))link=linklist()link.form(datalist)a=pb=[]while link.length()>0: b.append(link.search(a)) link.delete(a) a=a+p while a>=link.length(): a=a-link.length()print(b)
改错如下:
```python
class Node:
def __init__(self, data):
self.data = data
self.next = None
class LinkList:
def __init__(self):
self.head = None
self.tail = None
def isEmpty(self):
if self.head:
return False
else:
return True
def length(self):
if self.isEmpty():
return 0
else:
t = self.head
n = 1
while t.next:
if t.next == self.head:
break
t = t.next
n += 1
return n
def addhead(self, data):
node = Node(data)
if self.isEmpty():
self.head = node
self.tail = self.head
else:
node.next = self.head
self.head = node
self.tail.next = self.head
def addtail(self, data):
node = Node(data)
if self.isEmpty():
self.addhead(data)
else:
t = self.head
n = 1
l = self.length()
while n < l:
n += 1
t = t.next
t.next = node
node.next = self.head
self.tail = node
def delete(self, index):
if self.isEmpty():
print("The linked list is empty")
else:
t = self.head
l = self.length()
if index == 0:
self.head = t.next
self.tail.next = self.head
elif index == l - 1:
n = 1
while n < l - 1:
t = t.next
n += 1
t.next = self.head
self.tail = t
elif index > l - 1:
print("Out of range")
elif index < 0:
print("Wrong operation")
else:
n = 1
while n < index:
t = t.next
n += 1
a = t.next.next
t.next = a
def insert(self, data, index):
l = self.length()
if index == 0 or self.isEmpty():
self.addhead(data)
elif index >= l:
self.addtail(data)
else:
node = Node(data)
t = self.head
n = 1
while n < index:
t = t.next
n += 1
a = t.next
t.next = node
node.next = a
def search(self, a):
t = self.head
for i in range(a):
t = t.next
return t.data
def form(self, datalist):
self.addhead(datalist[0])
for i in range(1, len(datalist)):
self.addtail(datalist[i])
t = self.head
while t.next != self.head:
t = t.next
n, p = map(int, input().split(' '))
data = [i for i in range(1, n+1)]
print(data)
datalist = []
for i in range(len(data)):
datalist.append(data[i])
link = LinkList()
link.form(datalist)
a = p-1
b = []
while link.length() > 0:
b.append(link.search(a))
link.delete(a)
a += p-1
while a >= link.length():
a -= link.length()
print(b)
```
解释下这段代码 %前端混频(复混频克服镜像干扰,输出复信号) if ~isempty(states.Mixer) mixPhases = 2*pi*states.Mixer.freq*(0:length(signalRead))/samplingFreq+states.Mixer.phase; signalRead = signalRead.*exp(-1i*mixPhases(1:end-1)); states.Mixer.phase = mixPhases(end); end %前端滤波(将会造成一定时延,后处理时需考虑) if ~isempty(states.Filter) b = states.Filter.b; a = states.Filter.a; zf = states.Filter.zf; [signalRead,zf] = filter(b,a,signalRead,zf); states.Filter.zf = zf; end
这段代码包含两个部分,分别是前端混频和前端滤波。
前端混频的作用是将信号进行复混频处理,以克服镜像干扰,输出复信号。具体来说,它会检查对象的States.Mixer是否为空,如果不为空,则会根据Mixer的频率和相位计算混频的相位,然后将采样到的信号与相应的旋转因子相乘,从而实现信号的混频处理。这样做的作用是将信号从基带移动到中心频率附近,方便后续的处理。
前端滤波的作用是对信号进行滤波处理,以去除噪声或不需要的频率成分。具体来说,它会检查对象的States.Filter是否为空,如果不为空,则会从States.Filter中获取滤波器的系数和状态变量,然后调用MATLAB中的filter函数对信号进行滤波处理,输出滤波后的信号和更新后的状态变量。这样做的作用是提高信号的质量并降低噪声。需要注意的是,由于滤波会引入一定的时延,因此在后续的处理中需考虑这一点。
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