{"student_name":"wc10","student_id":"392","class_id":"class_four","subject":"gailv","grade":"99"} {"student_name":"wc11","student_id":"393","class_id":"class_four","subject":"gailv","grade":"100"} {"student_name":"wc12","student_id":"394","class_id":"class_four","subject":"gailv","grade":"101"}作为表table student_score_info ( student_name string, -- 学生姓名 student_id string, -- 学号 class_id string, -- 班级ID subject string, -- 科目名 grade int -- 科目成绩 )的数据源有问题吗
时间: 2023-07-02 13:22:48 浏览: 123
是的,这个数据源存在问题。这些数据应该以正确的格式输入到表中,而不是以JSON对象的形式。正确的格式应该是每行包含一个学生的信息,例如:
```
wc10,392,class_four,gailv,99
wc11,393,class_four,gailv,100
wc12,394,class_four,gailv,101
```
每列用逗号分隔,每行表示一个学生的信息。这样数据才能正确地被表读取和分析。
相关问题
{"student_name":"wc1","student_id":"383","class_id":"class_one","subject":"gaoshu","grade":"90"} {"student_name":"wc2","student_id":"384","class_id":"class_one","subject":"gaoshu","grade":"91"} {"student_name":"wc3","student_id":"385","class_id":"class_one","subject":"gaoshu","grade":"92"} {"student_name":"wc4","student_id":"386","class_id":"class_two","subject":"dawu","grade":"93"} {"student_name":"wc5","student_id":"387","class_id":"class_two","subject":"dawu","grade":"94"} {"student_name":"wc6","student_id":"388","class_id":"class_two","subject":"dawu","grade":"95"} {"student_name":"wc7","student_id":"389","class_id":"class_three","subject":"xiandai","grade":"96"} {"student_name":"wc8","student_id":"390","class_id":"class_three","subject":"xiandai","grade":"97"} {"student_name":"wc9","student_id":"391","class_id":"class_three","subject":"xiandai","grade":"98"} {"student_name":"wc10","student_id":"392","class_id":"class_four","subject":"gailv","grade":"99"} {"student_name":"wc11","student_id":"393","class_id":"class_four","subject":"gailv","grade":"100"} {"student_name":"wc12","student_id":"394","class_id":"class_four","subject":"gailv","grade":"101"}作为json对象的形式传入表table student_score_info ( student_name string, -- 学生姓名 student_id string, -- 学号 class_id string, -- 班级ID subject string, -- 科目名 grade int -- 科目成绩 )有问题吗
是的,这个JSON对象的形式传入表的方式也存在问题。与上一个问题相似,正确的方式是将每个学生的信息放在一个JSON对象中,每个JSON对象表示一个学生的信息,例如:
```
{"student_name":"wc1","student_id":"383","class_id":"class_one","subject":"gaoshu","grade":"90"}
{"student_name":"wc2","student_id":"384","class_id":"class_one","subject":"gaoshu","grade":"91"}
{"student_name":"wc3","student_id":"385","class_id":"class_one","subject":"gaoshu","grade":"92"}
{"student_name":"wc4","student_id":"386","class_id":"class_two","subject":"dawu","grade":"93"}
{"student_name":"wc5","student_id":"387","class_id":"class_two","subject":"dawu","grade":"94"}
{"student_name":"wc6","student_id":"388","class_id":"class_two","subject":"dawu","grade":"95"}
{"student_name":"wc7","student_id":"389","class_id":"class_three","subject":"xiandai","grade":"96"}
{"student_name":"wc8","student_id":"390","class_id":"class_three","subject":"xiandai","grade":"97"}
{"student_name":"wc9","student_id":"391","class_id":"class_three","subject":"xiandai","grade":"98"}
{"student_name":"wc10","student_id":"392","class_id":"class_four","subject":"gailv","grade":"99"}
{"student_name":"wc11","student_id":"393","class_id":"class_four","subject":"gailv","grade":"100"}
{"student_name":"wc12","student_id":"394","class_id":"class_four","subject":"gailv","grade":"101"}
```
每行包含一个学生的信息,用JSON对象表示,可以正确地被表读取和分析。
解释代码:function [V]=update_v(wmax,wmin,index_i,maxIterations,sizepop,pop,v,pbest,gbest,vmax,dimpop) c1=((0.5-2.5)*index_i/maxIterations)+2.5; %个体学习因子 随迭代次数增加,减小,防止过早期早收敛 c2=((2.5-0.5)*index_i/maxIterations)+0.5; %群体学习因子 随迭代次数增加,增大,增加后期收敛速度 w=wmax-(wmax-wmin)*(index_i)^2/(maxIterations)^2; % 随迭代次数增加减少,减少自身在迭代次数的影响因素,加快后期收敛速度,与精度 % dijian=(index_i)^2/maxIterations^2; for index_j = 1:sizepop for index_k=1:dimpop % %% 速度更新 r1=2*rand(1)-1; %-1到1随机值 r2=2*rand(1)-1; % %为增加计算速度,此处r1r2用之前的 % gailv=sign(((r1+r2)/4+0.5-0.2)-dijian*0.8);%最开始有80%的概率大于零,最后大于零的概率为0. % dijian_k=((index_k-1)^2/(dimpop-1)^2); % gailv_k=sign(((r1+r2)/4+0.5-0.2)-dijian_k*0.8); v(index_j,index_k) = ((w*v(index_j,index_k) + c1*r1*(pbest(index_j,index_k) - pop(index_j,index_k)) + c2*r2*(gbest(index_k) - pop(index_j,index_k)))); % if dis(index_k-1)*pop(index_j,index_k-1)>0||gailv>0||gailv_k>0||dis(index_k-1)*v(index_j,index_k-1)>0 % v(index_j,index_k)=-v(index_j,index_k); % end %% 限幅处理 if(v(index_j,index_k)>vmax(1,index_k)) v(index_j,index_k)=vmax(1,index_k); %容量速度超上限 elseif(v(index_j,index_k)<-vmax(1,index_k)) v(index_j,index_k)=vmax(1,index_k); %容量速度超下限 end end end V=v;%%循环结束后,将更新后的速度矩阵v赋值给输出变量V end
这段代码是一个粒子群优化算法中用于更新粒子速度的函数。它接收了一系列参数,包括最大和最小速度限制(wmax和wmin)、当前迭代次数(index_i)、种群大小(sizepop)、种群矩阵(pop)、当前速度矩阵(v)、个体历史最优位置矩阵(pbest)、全局最优位置向量(gbest)、速度限制向量(vmax)和维度大小(dimpop)。
在函数中,首先根据迭代次数计算个体学习因子c1和群体学习因子c2。这些因子随着迭代次数的增加而变化,以调整个体和群体对速度更新的影响。
接下来,根据当前迭代次数计算惯性权重w。随着迭代次数的增加,w逐渐减小,减少了自身在迭代过程中的影响,从而加快后期收敛速度。
然后,使用随机数r1和r2生成每个粒子的速度更新量。根据粒子群优化算法的原理,速度更新公式为:v = w * v + c1 * r1 * (pbest - pop) + c2 * r2 * (gbest - pop),其中w是惯性权重,c1和c2是学习因子,r1和r2是随机数,pbest是粒子的个体历史最优位置,pop是当前种群位置矩阵,gbest是全局最优位置。
接下来进行限幅处理,将更新后的速度v限制在最大和最小速度限制范围内。
最后,将更新后的速度矩阵V赋值给输出变量V,并返回。
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