C#中XML文档生成实例：Elevator Scheduler测试文件的生成详解
由于作为软件工程课pair project II (电梯调度程序)的志愿者，我负责为大家产生至关重要的用于最后评定各个pair的调度程序性能的测试数据(压力好大
)。
完整的源码下载（VS2010）：http://files.cnblogs.com/codingcrazy/GenerateElevTestData.rar
1. 要求
详细要求：http://www.cnblogs.com/xinz/archive/2010/11/28/1890300.html
3. Testing
TA will simulate a “rush hour” test. The “rush hour” test is to simulate the come-to-work and leave-work scenario in a business building, which has the following 2 parts (they can be run next to each other).
1) Simple test. 20 passengers
20 people going thru random floors within 5 minutes.
2) Come-to-work. 1000 total passengers
a) 80% of them goes from floor 0 and 1 to all other floors, the destination is distributed evenly.
The time each passenger arrives at the elevator can be emulated as a normal distribution.
b) 20% of them are going between any 2 floors of [2, 20], Very few people travel between 2 adjacent floors
(e.g. from floor 5 to 4). Other than this, the distribution is also even.
3) Leave-work. 1000 total passengers
a) 90% of them go from other floors to floor1 or floor0.
b) 10% of them travel between floors [2, 20], again, Very few people travel between 2 adjacent floors.
测试数据文件格式：XML文档描述的乘客信息，如下：
<?
xml version="1.0" encoding="utf-8"
?>
<
passengers
xmlns:xsi
="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd
="http://www.w3.org/2001/XMLSchema"
xmlns
="http://tempuri.org/passengers.xsd"
>
<
passenger
name
="SENXIANG"
comingtime
="50"
fromfloor
="10"
tofloor
="20"
weight
="60"
/>
<
passenger
name
="Piggy"
comingtime
="100"
fromfloor
="1"
tofloor
="15"
weight
="75"
/>
<
passenger
name
="Later"
comingtime
="10000"
fromfloor
="99"
tofloor
="15"
weight
="45"
/>
</
passengers
>
2. 正态分布随机数的产生
根据要求，需要模拟上班时和下班时的电梯乘客情况，使其满足正态分布：即在规定上班之前（下班时间之后）某个时间点乘客达到最高峰，两边依近似正态分布递减。因此，这里的核心需求是：如何产生满足正态分布的随机数？
这里使用Marsaglia方法（见维基百科：http://en.wikipedia.org/wiki/Normal_distribution，小节：Generating values from normal distribution）。
原理：Box-Muller方法：设有两个服从均匀分布U(0,1)的独立随机变量U和V，那么由下式得到的X和Y也是独立随机变量，并且都服从正态分布N(0,1)。
Marsaglia对Box-Muller方法进行了改进，使其不再需要进行三角函数的计算。Marsaglia使用的U和V是两个服从均匀分布U(-1,1)的独立随机变量，令
S = U2 + V2，如果S>=1则重新计算S，否则下面的X和Y就是服从标准正态分布N(0,1)的独立随机变量：
下面是按以上算法产生正态分布随机数的类：
//
//
Gaussian Random Number Generator class
//
ref.
http://blog.csdn.net/holym/archive/2006/05/16/741074.aspx
//
public
class
GaussianRNG
{
int
iset;
double
gset;
Random r1, r2;
public
GaussianRNG()
{
//
use unchecked to disable overflow check
r1
=
new
Random(
unchecked
((
int
)DateTime.Now.Ticks));
r2
=
new
Random(
~
unchecked
((
int
)DateTime.Now.Ticks));
iset
=
0
;
}
//
generate Gaussian random numbers of N(0,1)
public
double
Next()
{
double
fac, rsq, v1, v2;
if
(iset
==
0
)
{
do
{
v1
=
2.0
*
r1.NextDouble()
-
1.0
;
v2
=
2.0
*
r2.NextDouble()
-
1.0
;
rsq
=
v1
*
v1
+
v2
*
v2;
}
while
(rsq
>=
1.0
||
rsq
==
0.0
);
fac
=
Math.Sqrt(
-
2.0
*
Math.Log(rsq)
/
rsq);
gset
=
v1
*
fac;
iset
=
1
;
return
v2
*
fac;
}
else
{
iset
=
0
;
return
gset;
}
}
//
generate Gaussian random numbers of N(mu,sigma)
//
Note: the return values are constrained to between (mu-sigma) and (mu+sigma)
public
double
Next(
double
mu,
double
sigma)
{
double
x
=
Next();
while
(x
<
-
1
||
x
>
1
)
{
x
=
Next();
}
return
(mu
+
x
*
sigma);
}
}
3. XML文件的产生
由于原来测试程序框架中需要在XML中声明命名空间（因为要根据预先定义的xsd文件进行反序列化生成所需的passenger对象）。我没有找到在XML文件中直接写入命名空间的语句。因此偷懒先生成简单的XML文件，再用StreamReader将文件读入，用StreamWriter将其连同命名空间声明一同写入到目标XML文件。如果你有好的方法，请告诉我。下面是生成Come to work测试文件的代码：
static
void
GenerateData_ComeToWork()
{
Random rnd
=
new
Random();
GaussianRNG rnd_gaussian
=
new
GaussianRNG();
int
fromfloor;
int
tofloor;
int
highestFloor
=
20
;
try
{
using
(XmlTextWriter writer
=
new
XmlTextWriter(
"
temp2.xml
"
,
null
))
{
writer.Formatting
=
Formatting.Indented;
writer.WriteStartDocument();
writer.WriteStartElement(
"
passengers
"
);
//
Generate passenger info
for
(
int
i
=
1
; i
<=
800
; i
++
)
{
writer.WriteStartElement(
"
passenger
"
);
writer.WriteAttributeString(
"
name
"
,
string
.Format(
"
Xiao_{0}
"
, i));
//
passenger come to work in 1 hour
writer.WriteAttributeString(
"
comingtime
"
, Math.Ceiling(rnd_gaussian.Next(
1800
,
1800
)).ToString());
//
fromfloor: 0 or 1
writer.WriteAttributeString(
"
fromfloor
"
, rnd.Next(
2
).ToString());
//
tofloor: [2...20]
writer.WriteAttributeString(
"
tofloor
"
, rnd.Next(
2
, highestFloor
+
1
).ToString());
//
passenger weight form 45 to 120, average 70
writer.WriteAttributeString(
"
weight
"
, rnd.Next((i
<=
400
)
?
45
:
70
, (i
<=
400
)
?
70
:
120
).ToString());
writer.WriteEndElement();
}
for
(
int
i
=
801
; i
<=
1000
; i
++
)
{
writer.WriteStartElement(
"
passenger
"
);
writer.WriteAttributeString(
"
name
"
,
string
.Format(
"
Xiao_{0}
"
, i));
//
passenger come to work in 1 hour
writer.WriteAttributeString(
"
comingtime
"
, Math.Ceiling(rnd_gaussian.Next(
1800
,
1800
)).ToString());
//
Request: fromfloor != tofloor, very few people travel between adjacent floors
fromfloor
=
rnd.Next(
2
, highestFloor
+
1
);
while
((tofloor
=
rnd.Next(
2
, highestFloor
+
1
))
==
fromfloor)
;
if
(Math.Abs(fromfloor
-
tofloor)
==
1
&&
(rnd.Next(
101
)
/
100
)
<
80
)
{
fromfloor
=
rnd.Next(
2
, highestFloor
+
1
);
while
((tofloor
=
rnd.Next(
2
, highestFloor
+
1
))
==
fromfloor)
;
}
writer.WriteAttributeString(
"
fromfloor
"
, fromfloor.ToString());
writer.WriteAttributeString(
"
tofloor
"
, tofloor.ToString());
//
passenger weight form 45 to 120, average 70
writer.WriteAttributeString(
"
weight
"
, rnd.Next((i
<=
900
)
?
45
:
70
, (i
<=
900
)
?
70
:
120
).ToString());
writer.WriteEndElement();
}
writer.WriteEndElement();
writer.Flush();
writer.Close();
}
using
(StreamWriter sw
=
new
StreamWriter(
"
passenger2.xml
"
))
{
sw.Write(
"
<?xml version=\
"
1.0
\
"
encoding=\
"
utf
-
8
\
"
?>\r\n<passengers \r\n xmlns:xsi=\
"
http:
//
www.w3.org/2001/XMLSchema-instance\" \r\n xmlns:xsd=\"
http://www.w3.org/2001/XMLSchema
\" \r\n xmlns=\"
http://tempuri.org/passengers.xsd
\">\r\n");
using
(StreamReader sr
=
new
StreamReader(
"
temp2.xml
"
))
{
sr.ReadLine();
sr.ReadLine();
while
(sr.Peek()
>
0
)
{
sw.WriteLine(sr.ReadLine());
}
}
}
Console.WriteLine(
"
\nThe following file has been successfully created: passenger2.xml
"
);
}
catch
(Exception)
{
throw
;
}
}
by Xiaobin([email protected])